7 Property operating expenses
| | 2016 | 2015 |
Taxes | 1,591 | 1,691 |
Insurance | 80 | 211 |
Maintenance | 3,530 | 3,640 |
Valuation fees | 55 | 102 |
Property management fees | 904 | 1,247 |
Letting and lease renewal fees | 3,288 | 2,603 |
Other operating expenses | 3,602 | 3,257 |
Addition to provision for bad debts | 275 | 312 |
Total property operating expenses | 13,325 | 13,063 |
In 2016, € 0.2 million (2015: € 0.2 million) of the maintenance expenses related to unlet properties.