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 ) . .
1 . related revenues are included in 201cmarket making 201d in the consolidated statements of earnings . goldman sachs 2013 annual report 45 .
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
$ in millions year ended december 2013 year ended december 2012 year ended december 2011
compensation and benefits $ 12613 $ 12944 $ 12223
brokerage clearing exchange anddistribution fees 2341 2208 2463
market development 541 509 640
communications and technology 776 782 828
depreciation and amortization 1322 1738 1865
occupancy 839 875 1030
professional fees 930 867 992
insurance reserves1 176 598 529
other expenses 2931 2435 2072
total non-compensation expenses 9856 10012 10419
total operating expenses $ 22469 $ 22956 $ 22642
total staff at period-end 32900 32400 33300
what is the percentage change in staff number in 2013?