(30) Personnel expenses

The breakdown of personnel expenses is as follows:

Personnel Expenses
€ million 2012 2013
Wages and salaries 1,097 1,006
Social security contributions 193 194
Retirement benefit expenses 92 128
Social assistance benefits 10 11
  1,392 1,339

Total personnel expenses declined in 2013. The fact that personnel expenses were lower than in the previous year despite the higher average headcount and Group-wide salary increases was mainly due to adjustments to performance-related compensation. The personnel expenses shown here do not contain the interest portion of personnel-related provisions, especially pension provisions, which is reflected in the financial result (see Note [27]).