8. Operating Expenses
| Year ended 31 December 2011 |
Year ended 31 December 2010 |
|
|---|---|---|
| Electricity transmission | 17,010,116 | 16,813,340 |
| Purchased electricity | 15,295,151 | 13,032,523 |
| Personnel costs (Note 9) | 13,432,700 | 11,635,300 |
| Depreciation and amortization | 6,284,802 | 5,011,364 |
| Raw materials and supplies | 2,149,983 | 1,735,089 |
| Rent | 576,615 | 477,251 |
| Electricity for own needs | 481,654 | 441,100 |
| Repairs, maintenance and installation services | 467,218 | 533,581 |
| Taxes other than income tax | 348,930 | 337,303 |
| Transportation costs | 332,151 | 416,462 |
| Security | 272,384 | 214,618 |
| Allowance for impairment of accounts receivable | 477,586 | 272,690 |
| Information services | 187,485 | 221,586 |
| Insurance | 163,385 | 167,424 |
| Consulting, legal and audit services | 66,471 | 75,604 |
| Telecommunication services | 40,942 | 102,152 |
| Bad debt written-off | 21,237 | 6,120 |
| Membership fee | 6,413 | 9,140 |
| Outsourcing services | — | 763,246 |
| Other | 3,447,554 | 1,836,897 |
| 61,062,777 | 54,102,790 |
Other operating expenses include expense for accrual of provision for litigations and claims of RUB 1,041,516 thousand (2010: RUB 34 670 thousand).
Return to Notes to the Consolidated Financial Statements for the year ended 31 December 2011