management 2019s discussion and analysis net interest income 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 . 2011 versus 2010 . net interest income on the consolidated statements of earnings was $ 5.19 billion for 2011 , 6% ( 6 % ) lower than 2010 . the decrease compared with 2010 was primarily due to higher interest expense related to our long-term borrowings and higher dividend expense related to financial instruments sold , but not yet purchased , partially offset by an increase in interest income from higher yielding collateralized agreements . 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 . in the context of more difficult economic and financial conditions , the firm launched an initiative during the second quarter of 2011 to identify areas where we can operate more efficiently and reduce our operating expenses . during 2012 and 2011 , we announced targeted annual run rate compensation and non-compensation reductions of approximately $ 1.9 billion in aggregate . the table below presents our operating expenses and total staff. .

year ended december 2012: compensation and benefits: 12944
u.k . bank payrolltax: 2014
brokerage clearing exchange anddistribution fees: 2208
market development: 509
communications and technology: 782
depreciation and amortization: 1738
occupancy: 875
professional fees: 867
insurance reserves1: 598
other expenses: 2435
total non-compensation expenses: 10012
total operating expenses: 22956
total staff atperiod-end2: 32400
year ended december 2011: compensation and benefits: 12223
u.k . bank payrolltax: 2014
brokerage clearing exchange anddistribution fees: 2463
market development: 640
communications and technology: 828
depreciation and amortization: 1865
occupancy: 1030
professional fees: 992
insurance reserves1: 529
other expenses: 2072
total non-compensation expenses: 10419
total operating expenses: 22642
total staff atperiod-end2: 33300
year ended december 2010: compensation and benefits: 15376
u.k . bank payrolltax: 465
brokerage clearing exchange anddistribution fees: 2281
market development: 530
communications and technology: 758
depreciation and amortization: 1889
occupancy: 1086
professional fees: 927
insurance reserves1: 398
other expenses: 2559
total non-compensation expenses: 10428
total operating expenses: 26269
total staff atperiod-end2: 35700

total staff at period-end 2 32400 33300 35700 1 . related revenues are included in 201cmarket making 201d on the consolidated statements of earnings . 2 . includes employees , consultants and temporary staff . 48 goldman sachs 2012 annual report .

Questions:
what was the change in the number of staff from 2011 to 2012?
and what was the total number of staff in 2011?
how much, then, does that change represent in relation to this 2011 total?

Answers:
-900
33300
-2.7%