5. Our people

Our staff numbers averaged 133,903 for the year ended 31 December 2018 against 134,428 in 2017 and 132,657 in 2016. Their geographical distribution was as follows:


	2018		2017		2016
North America		25,990		27,399		27,246
UK		14,331		14,197		14,070
Western Continental Europe		26,825		25,700		24,996
Asia Pacific, Latin America, Africa & Middle East and Central & Eastern Europe		66,757		67,132		66,345
		133,903		134,428		132,657

Their reportable segment distribution was as follows:


	2018		2017		2016
Advertising and Media Investment Management		55,421		56,789		55,120
Data Investment Management		28,309		28,629		29,279
Public Relations & Public Affairs		9,048		9,082		9,054
Brand Consulting, Health & Wellness and Specialist Communications		41,125		39,928		39,204
		133,903		134,428		132,657

At the end of 2018, staff numbers were 134,281 (2017: 134,413, 2016: 134,341).

Staff costs include:


	2018 £m		2017 £m		2016 £m
Wages and salaries		5,710.0		5,832.3		5,395.6
Cash-based incentive plans		240.7		219.2		260.2
Share-based incentive plans (note 21)		84.8		105.0		106.5
Social security costs		717.5		720.3		658.1
Pension costs (note 22)		191.2		192.0		178.1
Severance		37.5		39.5		34.5
Other staff costs¹		1,190.9		1,210.7		1,151.9
		8,172.6		8,319.0		7,784.9

Note

Freelance and temporary staff costs are included in other staff costs.

Included above are charges of £2.0 million (2017: £12.3 million, 2016: £15.5 million) for share-based incentive plans in respect of key management personnel (who comprise the Directors of the Group). Total compensation received by key management personnel in respect of 2018 was £6.2 million (2017: £17.8 million, 2016: £57.5 million) of which £0.4 million (2017: £0.7 million, 2016: £0.7 million) were pension contributions. The value of the EPSP awards, which vest in the year following the end of the five-year performance period, is included in total compensation in the year the relevant five-year performance period ends.