Exhibit A

Transactions by Reporting Persons in the last 60 days not previously reported

Beneficial Ownership	Purchase or Sale	Quantity	Transaction Date	Price per Share (including commission)		How Effected
Relational Investors LLC	Sale	1,970	4/29/2013	$	74.58	Open Market
Relational Investors LLC	Sale	960	4/29/2013	$	74.62	Open Market
Relational Investors LLC	Sale	1,010	4/29/2013	$	74.43	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	9,525	4/29/2013	$	74.58	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	4,393	4/29/2013	$	74.58	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	6,787	4/29/2013	$	74.62	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	7,131	4/29/2013	$	74.43	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	4,213	4/29/2013	$	74.58	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	6,315	4/29/2013	$	74.58	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	5,134	4/29/2013	$	74.62	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	1,110	4/29/2013	$	74.43	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	4,285	4/29/2013	$	74.43	Open Market
Relational Investors LLC	Sale	4,565	4/29/2013	$	74.58	Open Market
Relational Investors LLC	Sale	2,227	4/29/2013	$	74.62	Open Market
Relational Investors LLC	Sale	2,339	4/29/2013	$	74.43	Open Market
Relational Coast Partners, L.P.	Sale	2,554	4/29/2013	$	74.58	Open Market
Relational Coast Partners, L.P.	Sale	1,246	4/29/2013	$	74.62	Open Market
Relational Coast Partners, L.P.	Sale	1,308	4/29/2013	$	74.43	Open Market
Relational Fund Partners, L.P.	Sale	142	4/29/2013	$	74.58	Open Market
Relational Fund Partners, L.P.	Sale	67	4/29/2013	$	74.62	Open Market
Relational Fund Partners, L.P.	Sale	72	4/29/2013	$	74.43	Open Market
Relational Investors XV, L.P.	Sale	1,397	4/29/2013	$	74.58	Open Market
Relational Investors XV, L.P.	Sale	681	4/29/2013	$	74.62	Open Market
Relational Investors XV, L.P.	Sale	716	4/29/2013	$	74.43	Open Market
Relational Investors XVI, L.P.	Sale	608	4/29/2013	$	74.58	Open Market
Relational Investors XVI, L.P.	Sale	296	4/29/2013	$	74.62	Open Market
Relational Investors XVI, L.P.	Sale	312	4/29/2013	$	74.43	Open Market
Relational Investors XX, L.P.	Sale	1,182	4/29/2013	$	74.58	Open Market
Relational Investors XX, L.P.	Sale	576	4/29/2013	$	74.62	Open Market
Relational Investors XX, L.P.	Sale	606	4/29/2013	$	74.43	Open Market
Relational Investors XXIII, L.P.	Sale	1,676	4/29/2013	$	74.58	Open Market
Relational Investors XXIII, L.P.	Sale	817	4/29/2013	$	74.62	Open Market
Relational Investors XXIII, L.P.	Sale	859	4/29/2013	$	74.43	Open Market
Relational Investors IX, L.P.	Sale	1,934	4/29/2013	$	74.58	Open Market
Relational Investors IX, L.P.	Sale	829	4/29/2013	$	74.58	Open Market
Relational Investors IX, L.P.	Sale	1,348	4/29/2013	$	74.62	Open Market
Relational Investors IX, L.P.	Sale	1,416	4/29/2013	$	74.43	Open Market
Relational Investors LLC	Sale	8,697	4/29/2013	$	74.58	Open Market
Relational Investors LLC	Sale	4,240	4/29/2013	$	74.62	Open Market
Relational Investors LLC	Sale	4,457	4/29/2013	$	74.43	Open Market
Relational Investors LLC	Purchase	2,215	5/1/2013	$	68.14	Open Market
Relational Investors LLC	Purchase	3,010	5/1/2013	$	68.15	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	7,477	5/1/2013	$	68.14	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	10,163	5/1/2013	$	68.15	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	5,332	5/1/2013	$	68.14	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	7,247	5/1/2013	$	68.15	Open Market
Relational Investors LLC	Purchase	11,235	5/1/2013	$	68.14	Open Market

Relational Investors LLC	Purchase	15,265	5/1/2013	$	68.15	Open Market
Relational Coast Partners, L.P.	Purchase	1,767	5/1/2013	$	68.14	Open Market
Relational Coast Partners, L.P.	Purchase	2,402	5/1/2013	$	68.15	Open Market
Relational Fund Partners, L.P.	Purchase	137	5/1/2013	$	68.14	Open Market
Relational Fund Partners, L.P.	Purchase	187	5/1/2013	$	68.15	Open Market
RH Fund 1, L.P.	Purchase	3,174	5/1/2013	$	68.14	Open Market
RH Fund 1, L.P.	Purchase	4,315	5/1/2013	$	68.15	Open Market
Relational Investors XV, L.P.	Purchase	1,649	5/1/2013	$	68.14	Open Market
Relational Investors XV, L.P.	Purchase	2,241	5/1/2013	$	68.15	Open Market
Relational Investors XVI, L.P.	Purchase	976	5/1/2013	$	68.14	Open Market
Relational Investors XVI, L.P.	Purchase	1,327	5/1/2013	$	68.15	Open Market
Relational Investors XX, L.P.	Purchase	1,682	5/1/2013	$	68.14	Open Market
Relational Investors XX, L.P.	Purchase	2,286	5/1/2013	$	68.15	Open Market
Relational Investors XXIII, L.P.	Purchase	2,408	5/1/2013	$	68.14	Open Market
Relational Investors XXIII, L.P.	Purchase	3,273	5/1/2013	$	68.15	Open Market
Relational Investors IX, L.P.	Purchase	2,164	5/1/2013	$	68.14	Open Market
Relational Investors IX, L.P.	Purchase	2,941	5/1/2013	$	68.15	Open Market
Relational Investors LLC	Purchase	6,652	5/1/2013	$	68.14	Open Market
Relational Investors LLC	Purchase	9,042	5/1/2013	$	68.15	Open Market
Relational Investors LLC	Purchase	23,277	5/2/2013	$	70.25	Open Market
Relational Investors LLC	Purchase	5,671	5/2/2013	$	69.66	Open Market
Relational Investors LLC	Purchase	2,955	5/2/2013	$	70.28	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	78,578	5/2/2013	$	70.25	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	19,143	5/2/2013	$	69.66	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	9,977	5/2/2013	$	70.28	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	56,036	5/2/2013	$	70.25	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	13,651	5/2/2013	$	69.66	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	7,115	5/2/2013	$	70.28	Open Market
Relational Investors LLC	Purchase	117,979	5/2/2013	$	70.25	Open Market
Relational Investors LLC	Purchase	28,745	5/2/2013	$	69.66	Open Market
Relational Investors LLC	Purchase	14,985	5/2/2013	$	70.28	Open Market
Relational Coast Partners, L.P.	Purchase	18,573	5/2/2013	$	70.25	Open Market
Relational Coast Partners, L.P.	Purchase	4,525	5/2/2013	$	69.66	Open Market
Relational Coast Partners, L.P.	Purchase	2,358	5/2/2013	$	70.28	Open Market
Relational Fund Partners, L.P.	Purchase	1,455	5/2/2013	$	70.25	Open Market
Relational Fund Partners, L.P.	Purchase	354	5/2/2013	$	69.66	Open Market
Relational Fund Partners, L.P.	Purchase	184	5/2/2013	$	70.28	Open Market
RH Fund 1, L.P.	Purchase	33,363	5/2/2013	$	70.25	Open Market
RH Fund 1, L.P.	Purchase	8,128	5/2/2013	$	69.66	Open Market
RH Fund 1, L.P.	Purchase	4,236	5/2/2013	$	70.28	Open Market
Relational Investors XV, L.P.	Purchase	17,334	5/2/2013	$	70.25	Open Market
Relational Investors XV, L.P.	Purchase	4,223	5/2/2013	$	69.66	Open Market
Relational Investors XV, L.P.	Purchase	2,201	5/2/2013	$	70.28	Open Market
Relational Investors XVI, L.P.	Purchase	10,266	5/2/2013	$	70.25	Open Market
Relational Investors XVI, L.P.	Purchase	2,501	5/2/2013	$	69.66	Open Market
Relational Investors XVI, L.P.	Purchase	1,303	5/2/2013	$	70.28	Open Market
Relational Investors XX, L.P.	Purchase	17,680	5/2/2013	$	70.25	Open Market

Relational Investors XX, L.P.	Purchase	4,307	5/2/2013	$	69.66	Open Market
Relational Investors XX, L.P.	Purchase	2,244	5/2/2013	$	70.28	Open Market
Relational Investors XXIII, L.P.	Purchase	25,309	5/2/2013	$	70.25	Open Market
Relational Investors XXIII, L.P.	Purchase	6,165	5/2/2013	$	69.66	Open Market
Relational Investors XXIII, L.P.	Purchase	3,213	5/2/2013	$	70.28	Open Market
Relational Investors IX, L.P.	Purchase	15,918	5/2/2013	$	70.25	Open Market
Relational Investors IX, L.P.	Purchase	6,822	5/2/2013	$	70.25	Open Market
Relational Investors IX, L.P.	Purchase	5,540	5/2/2013	$	69.66	Open Market
Relational Investors IX, L.P.	Purchase	2,887	5/2/2013	$	70.28	Open Market
Relational Investors LLC	Purchase	69,910	5/2/2013	$	70.25	Open Market
Relational Investors LLC	Purchase	17,031	5/2/2013	$	69.66	Open Market
Relational Investors LLC	Purchase	8,876	5/2/2013	$	70.28	Open Market
Relational Investors LLC	Purchase	18,978	5/3/2013	$	73.12	Open Market
Relational Investors LLC	Purchase	7,590	5/3/2013	$	73.17	Open Market
Relational Investors LLC	Purchase	13,830	5/3/2013	$	73.16	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	64,063	5/3/2013	$	73.12	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	25,623	5/3/2013	$	73.17	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	46,687	5/3/2013	$	73.16	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	45,684	5/3/2013	$	73.12	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	18,272	5/3/2013	$	73.17	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	33,293	5/3/2013	$	73.16	Open Market
Relational Investors LLC	Purchase	96,181	5/3/2013	$	73.12	Open Market
Relational Investors LLC	Purchase	38,477	5/3/2013	$	73.17	Open Market
Relational Investors LLC	Purchase	70,099	5/3/2013	$	73.16	Open Market
Relational Coast Partners, L.P.	Purchase	15,143	5/3/2013	$	73.12	Open Market
Relational Coast Partners, L.P.	Purchase	6,056	5/3/2013	$	73.17	Open Market
Relational Coast Partners, L.P.	Purchase	11,035	5/3/2013	$	73.16	Open Market
Relational Fund Partners, L.P.	Purchase	1,187	5/3/2013	$	73.12	Open Market
Relational Fund Partners, L.P.	Purchase	474	5/3/2013	$	73.17	Open Market
Relational Fund Partners, L.P.	Purchase	865	5/3/2013	$	73.16	Open Market
RH Fund 1, L.P.	Purchase	27,200	5/3/2013	$	73.12	Open Market
RH Fund 1, L.P.	Purchase	10,879	5/3/2013	$	73.17	Open Market
RH Fund 1, L.P.	Purchase	19,822	5/3/2013	$	73.16	Open Market
Relational Investors XV, L.P.	Purchase	14,132	5/3/2013	$	73.12	Open Market
Relational Investors XV, L.P.	Purchase	5,652	5/3/2013	$	73.17	Open Market
Relational Investors XV, L.P.	Purchase	10,299	5/3/2013	$	73.16	Open Market
Relational Investors XVI, L.P.	Purchase	8,369	5/3/2013	$	73.12	Open Market
Relational Investors XVI, L.P.	Purchase	3,347	5/3/2013	$	73.17	Open Market
Relational Investors XVI, L.P.	Purchase	6,099	5/3/2013	$	73.16	Open Market
Relational Investors XX, L.P.	Purchase	14,415	5/3/2013	$	73.12	Open Market
Relational Investors XX, L.P.	Purchase	5,765	5/3/2013	$	73.17	Open Market
Relational Investors XX, L.P.	Purchase	10,505	5/3/2013	$	73.16	Open Market
Relational Investors XXIII, L.P.	Purchase	20,634	5/3/2013	$	73.12	Open Market
Relational Investors XXIII, L.P.	Purchase	8,253	5/3/2013	$	73.17	Open Market
Relational Investors XXIII, L.P.	Purchase	15,037	5/3/2013	$	73.16	Open Market
Relational Investors IX, L.P.	Purchase	18,539	5/3/2013	$	73.12	Open Market
Relational Investors IX, L.P.	Purchase	5,190	5/3/2013	$	73.17	Open Market
Relational Investors IX, L.P.	Purchase	2,225	5/3/2013	$	73.17	Open Market
Relational Investors IX, L.P.	Purchase	13,511	5/3/2013	$	73.16	Open Market
Relational Investors LLC	Purchase	56,996	5/3/2013	$	73.12	Open Market
Relational Investors LLC	Purchase	22,797	5/3/2013	$	73.17	Open Market
Relational Investors LLC	Purchase	41,537	5/3/2013	$	73.16	Open Market
Relational Investors LLC	Purchase	9,274	5/6/2013	$	73.76	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	31,307	5/6/2013	$	73.76	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	22,326	5/6/2013	$	73.76	Open Market
Relational Investors LLC	Purchase	47,000	5/6/2013	$	73.76	Open Market
Relational Coast Partners, L.P.	Purchase	7,400	5/6/2013	$	73.76	Open Market
Relational Fund Partners, L.P.	Purchase	580	5/6/2013	$	73.76	Open Market
RH Fund 1, L.P.	Purchase	13,293	5/6/2013	$	73.76	Open Market
Relational Investors XV, L.P.	Purchase	6,907	5/6/2013	$	73.76	Open Market
Relational Investors XVI, L.P.	Purchase	4,091	5/6/2013	$	73.76	Open Market
Relational Investors XX, L.P.	Purchase	7,045	5/6/2013	$	73.76	Open Market
Relational Investors XXIII, L.P.	Purchase	10,084	5/6/2013	$	73.76	Open Market
Relational Investors IX, L.P.	Purchase	9,060	5/6/2013	$	73.76	Open Market
Relational Investors LLC	Purchase	27,854	5/6/2013	$	73.76	Open Market