management 2019s discussion and analysis 110 jpmorgan chase & co./2013 annual report 2012 compared with 2011 net loss was $ 2.0 billion , compared with a net income of $ 919 million in the prior year . private equity reported net income of $ 292 million , compared with net income of $ 391 million in the prior year . net revenue was $ 601 million , compared with $ 836 million in the prior year , due to lower unrealized and realized gains on private investments , partially offset by higher unrealized gains on public securities . noninterest expense was $ 145 million , down from $ 238 million in the prior year . treasury and cio reported a net loss of $ 2.1 billion , compared with net income of $ 1.3 billion in the prior year . net revenue was a loss of $ 3.1 billion , compared with net revenue of $ 3.2 billion in the prior year . the current year loss reflected $ 5.8 billion of losses incurred by cio from the synthetic credit portfolio for the six months ended june 30 , 2012 , and $ 449 million of losses from the retained index credit derivative positions for the three months ended september 30 , 2012 . these losses were partially offset by securities gains of $ 2.0 billion . the current year revenue reflected $ 888 million of extinguishment gains related to the redemption of trust preferred securities , which are included in all other income in the above table . the extinguishment gains were related to adjustments applied to the cost basis of the trust preferred securities during the period they were in a qualified hedge accounting relationship . net interest income was negative $ 683 million , compared with $ 1.4 billion in the prior year , primarily reflecting the impact of lower portfolio yields and higher deposit balances across the firm . other corporate reported a net loss of $ 221 million , compared with a net loss of $ 821 million in the prior year . noninterest revenue of $ 1.8 billion was driven by a $ 1.1 billion benefit for the washington mutual bankruptcy settlement , which is included in all other income in the above table , and a $ 665 million gain from the recovery on a bear stearns-related subordinated loan . noninterest expense of $ 3.8 billion was up $ 1.0 billion compared with the prior year . the current year included expense of $ 3.7 billion for additional litigation reserves , largely for mortgage-related matters . the prior year included expense of $ 3.2 billion for additional litigation reserves . treasury and cio overview treasury and cio are predominantly responsible for measuring , monitoring , reporting and managing the firm 2019s liquidity , funding and structural interest rate and foreign exchange risks , as well as executing the firm 2019s capital plan . 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 . 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 and htm investment securities portfolios ( the 201cinvestment securities portfolio 201d ) . cio also uses derivatives , as well as securities that are not classified as afs or htm , to meet the firm 2019s asset-liability management objectives . for further information on derivatives , see note 6 on pages 220 2013233 of this annual report . for further information about securities not classified within the afs or htm portfolio , see note 3 on pages 195 2013215 of this annual report . the treasury and cio investment securities portfolio primarily consists of u.s . and non-u.s . government securities , agency and non-agency mortgage-backed securities , other asset-backed securities , corporate debt securities and obligations of u.s . states and municipalities . at december 31 , 2013 , the total treasury and cio investment securities portfolio was $ 347.6 billion ; the average credit rating of the securities comprising the treasury and cio investment securities portfolio 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 249 2013254 of this annual report for further information on the details of the firm 2019s investment securities portfolio . for further information on liquidity and funding risk , see liquidity risk management on pages 168 2013173 of this annual report . for information on interest rate , foreign exchange and other risks , treasury and cio value-at-risk ( 201cvar 201d ) and the firm 2019s structural interest rate-sensitive revenue at risk , see market risk management on pages 142 2013148 of this annual report . selected income statement and balance sheet data as of or for the year ended december 31 , ( in millions ) 2013 2012 2011 .
based on the selected financial statement data what was the variance between the mortgage loans average and period-end balance
( a ) period-end investment securities included held-to-maturity balance of $ 24.0 billion at december 31 , 2013 . held-to-maturity balances for the other periods were not material. .