25 Average number of employees and personnel costs (XLS:) Download 2019 2018 2017 GROUP (TOTAL) 212,846 216,369 216,454 Germany 96,018 100,227 103,174 International 116,827 116,142 113,280 Non-civil servants 200,174 202,010 200,673 Civil servants (domestic, active service relationship) 12,672 14,359 15,781 Trainees and students on cooperative degree courses 6,136 5,713 6,559 PERSONNEL COSTS millions of € 16,723 16,436 15,504 Of which: wages and salaries millions of € 13,655 13,507 12,552 Of which: social security contributions and pension benefit costs millions of € 3,068 2,929 2,952 The average headcount decreased by 1.6 percent compared with the prior year. It decreased in Germany by 4.2 percent, due in particular to efficiency enhancement measures and the take-up of socially responsible instruments in connection with staff restructuring in the Germany operating segment and the domestic parts of the Group Headquarters & Group Services and Systems Solutions segments. By contrast, the average headcount outside Germany increased slightly by 0.6 percent. Here, the international share increased in all segments, with the exception of Europe, where the average international headcount decreased by 4.2 percent; in the Systems Solutions operating segment the increase was due to the first-time inclusion and expansion of a service unit in India. The total number of employees in the United States operating segment increased primarily due to ongoing growth in the business. The substantial increase in the Group Development operating segment is attributable to the inclusion of Tele2 Netherlands in the Netherlands. Personnel costs increased by 1.7 percent year-on-year, primarily due to developments in the United States operating segment: the development in exchange rates on the one hand, and the increase in salaries and a slight growth in headcount on the other. The Group Development and Europe operating segments also recorded increases thanks to the acquisition of Tele2 Netherlands and UPC Austria, both of which were included for the full financial year for the first time. The three segments mentioned above also recorded an increase in costs for restructuring. In all other segments, lower headcounts resulted in reduced personnel costs, offset in part by salary increases agreed in the collective agreements concluded in 2018. These segments also saw slightly lower expenses for staff restructuring measures in 2019.