what is the net interest income in 2011?
management 2019s discussion and analysis net interest income 2013 versus 2012 . net interest income on the consolidated statements of earnings was $ 3.39 billion for 2013 , 13% ( 13 % ) lower than 2012 . the decrease compared with 2012 was primarily due to lower average yields on financial instruments owned , at fair value , partially offset by lower interest expense on financial instruments sold , but not yet purchased , at fair value and collateralized financings . 2012 versus 2011 . net interest income on the consolidated statements of earnings was $ 3.88 billion for 2012 , 25% ( 25 % ) lower than 2011 . the decrease compared with 2011 was primarily due to lower average yields on financial instruments owned , at fair value and collateralized agreements . see 201cstatistical disclosures 2014 distribution of assets , liabilities and shareholders 2019 equity 201d for further information about our sources of net interest income . operating expenses our operating expenses are primarily influenced by compensation , headcount and levels of business activity . compensation and benefits includes salaries , discretionary compensation , amortization of equity awards and other items such as benefits . discretionary compensation is significantly impacted by , among other factors , the level of net revenues , overall financial performance , prevailing labor markets , business mix , the structure of our share-based compensation programs and the external environment . the table below presents our operating expenses and total staff ( which includes employees , consultants and temporary staff ) . .

|  | Year Ended December |
| :--- | :--- |
| <i>$ in millions</i> | 2013 | 2012 | 2011 |
| Compensation and benefits | $12,613 | $12,944 | $12,223 |
| Brokerage, clearing, exchange anddistribution fees | 2,341 | 2,208 | 2,463 |
| Market development | 541 | 509 | 640 |
| Communications and technology | 776 | 782 | 828 |
| Depreciation and amortization | 1,322 | 1,738 | 1,865 |
| Occupancy | 839 | 875 | 1,030 |
| Professional fees | 930 | 867 | 992 |
| Insurance reserves<sup>1</sup> | 176 | 598 | 529 |
| Other expenses | 2,931 | 2,435 | 2,072 |
| Total non-compensation expenses | 9,856 | 10,012 | 10,419 |
| Total operating expenses | $22,469 | $22,956 | $22,642 |
| Total staff at period-end | 32,900 | 32,400 | 33,300 |

1 . related revenues are included in 201cmarket making 201d in the consolidated statements of earnings . goldman sachs 2013 annual report 45 .

interest_income = 100 - 25
interest_expense = 3.88 / interest_income
answer = interest_expense * 100