10. Operating costs

  for the year ended
 Note31 December 2016 31 December 2015
Technical costs and cost of settlements with telecommunication operators 1,938.72,141.0
Depreciation, amortization, impairment and liquidation 1,971.51,699.3
Cost of equipment sold 1,354.71,332.8
Content costs 1,114.21,065.9
Distribution, marketing, customer relation management and retention costs 827.8802.6
Salaries and employee-related costsa570.5550.2
Cost of debt collection services and bad debt allowance and receivables written off 46.962.6
Other costs 245.0213.5
Total  8,069.37,867.9

A) Salaries and employee-related costs

 for the year ended
 31 December 2016 31 December 2015
Salaries481.4464.1
Social security contributions73.470.1
Other employee-related costs15.716.0
Total570.5550.2
 

Average headcount of non-production employees*

 for the year ended
 31 December 2016 31 December 2015
Employment contracts (full-time equivalents)5,0105,033

* excluding workers who did not perform work in the reporting period due to long-term absences