Quarterly financial data (unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Quarterly financial data is summarized as follows (in millions, except per-share data):


	2020 Quarters ended
	December 31		September 30		June 30		March 31
Product sales	$	6,334	$	6,104	$	5,908	$	5,894
Gross profit from product sales	$	4,737	$	4,543	$	4,420	$	4,381
Net income	$	1,615	$	2,021	$	1,803	$	1,825
Earnings per share:
Basic	$	2.78	$	3.45	$	3.07	$	3.09
Diluted	$	2.76	$	3.43	$	3.05	$	3.07

	2019 Quarters ended
	December 31		September 30		June 30		March 31
Product sales	$	5,881	$	5,463	$	5,574	$	5,286
Gross profit from product sales	$	4,628	$	4,427	$	4,562	$	4,231
Net income	$	1,703	$	1,968	$	2,179	$	1,992
Earnings per share:
Basic	$	2.87	$	3.29	$	3.59	$	3.20
Diluted	$	2.85	$	3.27	$	3.57	$	3.18