jpmorgan chase & co./2012 annual report 103 2011 compared with 2010 net income was $ 822 million , compared with $ 1.3 billion in the prior year . private equity reported net income of $ 391 million , compared with $ 588 million in the prior year . net revenue was $ 836 million , a decrease of $ 403 million , primarily related to net write-downs on private investments and the absence of prior year gains on sales . noninterest expense was $ 238 million , a decrease of $ 85 million from the prior treasury and cio reported net income of $ 1.3 billion , compared with net income of $ 3.6 billion in the prior year . net revenue was $ 3.2 billion , including $ 1.4 billion of security gains . net interest income in 2011 was lower compared with 2010 , primarily driven by repositioning of the investment securities portfolio and lower funding benefits from financing the portfolio . other corporate reported a net loss of $ 918 million , compared with a net loss of $ 2.9 billion in the prior year . net revenue was $ 103 million , compared with a net loss of $ 467 million in the prior year . noninterest expense was $ 2.9 billion which included $ 3.2 billion of additional litigation reserves , predominantly for mortgage-related matters . noninterest expense in the prior year was $ 5.5 billion which included $ 5.7 billion of additional litigation reserves . treasury and cio overview treasury and cio are predominantly responsible for measuring , monitoring , reporting and managing the firm 2019s liquidity , funding , capital and structural interest rate and foreign exchange risks . the risks managed by treasury and cio arise from the activities undertaken by the firm 2019s four major reportable business segments to serve their respective client bases , which generate both on- and off- balance sheet assets and liabilities . treasury is responsible for , among other functions , funds transfer pricing . funds transfer pricing is used to transfer structural interest rate risk and foreign exchange risk of the firm to treasury and cio and allocate interest income and expense to each business based on market rates . cio , through its management of the investment portfolio , generates net interest income to pay the lines of business market rates . any variance ( whether positive or negative ) between amounts generated by cio through its investment portfolio activities and amounts paid to or received by the lines of business are retained by cio , and are not reflected in line of business segment results . treasury and cio activities operate in support of the overall firm . cio achieves the firm 2019s asset-liability management objectives generally by investing in high-quality securities that are managed for the longer-term as part of the firm 2019s afs investment portfolio . unrealized gains and losses on securities held in the afs portfolio are recorded in other comprehensive income . for further information about securities in the afs portfolio , see note 3 and note 12 on pages 196 2013214 and 244 2013248 , respectively , of this annual report . cio also uses securities that are not classified within the afs portfolio , as well as derivatives , to meet the firm 2019s asset-liability management objectives . securities not classified within the afs portfolio are recorded in trading assets and liabilities ; realized and unrealized gains and losses on such securities are recorded in the principal transactions revenue line in the consolidated statements of income . for further information about securities included in trading assets and liabilities , see note 3 on pages 196 2013214 of this annual report . derivatives used by cio are also classified as trading assets and liabilities . for further information on derivatives , including the classification of realized and unrealized gains and losses , see note 6 on pages 218 2013227 of this annual report . cio 2019s afs portfolio consists of u.s . and non-u.s . government securities , agency and non-agency mortgage-backed securities , other asset-backed securities and corporate and municipal debt securities . treasury 2019s afs portfolio consists of u.s . and non-u.s . government securities and corporate debt securities . at december 31 , 2012 , the total treasury and cio afs portfolios were $ 344.1 billion and $ 21.3 billion , respectively ; the average credit rating of the securities comprising the treasury and cio afs portfolios was aa+ ( based upon external ratings where available and where not available , based primarily upon internal ratings that correspond to ratings as defined by s&p and moody 2019s ) . see note 12 on pages 244 2013248 of this annual report for further information on the details of the firm 2019s afs portfolio . for further information on liquidity and funding risk , see liquidity risk management on pages 127 2013133 of this annual report . for information on interest rate , foreign exchange and other risks , and cio var and the firm 2019s nontrading interest rate-sensitive revenue at risk , see market risk management on pages 163 2013169 of this annual report . selected income statement and balance sheet data as of or for the year ended december 31 , ( in millions ) 2012 2011 2010 securities gains ( a ) $ 2028 $ 1385 $ 2897 investment securities portfolio ( average ) 358029 330885 323673 investment securities portfolio ( period 2013end ) 365421 355605 310801 .

Table: as of or for the year ended december 31 ( in millions ) 2012 2011 2010 securities gains ( a ) $ 2028 $ 1385 $ 2897 investment securities portfolio ( average ) 358029 330885 323673 investment securities portfolio ( period 2013end ) 365421 355605 310801 mortgage loans ( average ) 10241 13006 9004 mortgage loans ( period-end ) 7037 13375 10739

( a ) reflects repositioning of the investment securities portfolio. .

Question: what was the private equity bussiness arm's 2011 efficiency ratio?
Answer: 28.47%
Calculation: divide(238, 836)