7 Property operating expenses
| | 2019 | 2018 |
Taxes | 1,326 | 1,980 |
Insurance | 230 | 182 |
Maintenance | 4,770 | 4,534 |
Valuation fees | 124 | 73 |
Property management fees | 895 | 1,083 |
Letting and lease renewal fees | 2,072 | 2,755 |
Other operating expenses | 3,658 | 4,459 |
Addition to provision for bad debts | 132 | (26) |
Total property operating expenses | 13,207 | 15,040 |
In 2019, € 0.8 million (2018: € 0.1 million) of the maintenance expenses related to unlet properties.