{"pre_text": ["mandatorily redeemable securities of subsidiary trusts total mandatorily redeemable securities of subsidiary trusts ( trust preferred securities ) , which qualify as tier 1 capital , were $ 23.899 billion at december 31 , 2008 , as compared to $ 23.594 billion at december 31 , 2007 .", "in 2008 , citigroup did not issue any new enhanced trust preferred securities .", "the frb issued a final rule , with an effective date of april 11 , 2005 , which retains trust preferred securities in tier 1 capital of bank holding companies , but with stricter quantitative limits and clearer qualitative standards .", "under the rule , after a five-year transition period , the aggregate amount of trust preferred securities and certain other restricted core capital elements included in tier 1 capital of internationally active banking organizations , such as citigroup , would be limited to 15% ( 15 % ) of total core capital elements , net of goodwill , less any associated deferred tax liability .", "the amount of trust preferred securities and certain other elements in excess of the limit could be included in tier 2 capital , subject to restrictions .", "at december 31 , 2008 , citigroup had approximately 11.8% ( 11.8 % ) against the limit .", "the company expects to be within restricted core capital limits prior to the implementation date of march 31 , 2009 .", "the frb permits additional securities , such as the equity units sold to adia , to be included in tier 1 capital up to 25% ( 25 % ) ( including the restricted core capital elements in the 15% ( 15 % ) limit ) of total core capital elements , net of goodwill less any associated deferred tax liability .", "at december 31 , 2008 , citigroup had approximately 16.1% ( 16.1 % ) against the limit .", "the frb granted interim capital relief for the impact of adopting sfas 158 at december 31 , 2008 and december 31 , 2007 .", "the frb and the ffiec may propose amendments to , and issue interpretations of , risk-based capital guidelines and reporting instructions .", "these may affect reported capital ratios and net risk-weighted assets .", "capital resources of citigroup 2019s depository institutions citigroup 2019s subsidiary depository institutions in the united states are subject to risk-based capital guidelines issued by their respective primary federal bank regulatory agencies , which are similar to the frb 2019s guidelines .", "to be 201cwell capitalized 201d under federal bank regulatory agency definitions , citigroup 2019s depository institutions must have a tier 1 capital ratio of at least 6% ( 6 % ) , a total capital ( tier 1 + tier 2 capital ) ratio of at least 10% ( 10 % ) and a leverage ratio of at least 5% ( 5 % ) , and not be subject to a regulatory directive to meet and maintain higher capital levels .", "at december 31 , 2008 , all of citigroup 2019s subsidiary depository institutions were 201cwell capitalized 201d under the federal regulatory agencies 2019 definitions , including citigroup 2019s primary depository institution , citibank , n.a. , as noted in the following table : citibank , n.a .", "components of capital and ratios under regulatory guidelines in billions of dollars at year end 2008 2007 ."], "post_text": ["leverage ratio ( 1 ) 5.82 6.65 ( 1 ) tier 1 capital divided by adjusted average assets .", "citibank , n.a .", "had a net loss for 2008 amounting to $ 6.2 billion .", "during 2008 , citibank , n.a .", "received contributions from its parent company of $ 6.1 billion .", "citibank , n.a .", "did not issue any additional subordinated notes in 2008 .", "total subordinated notes issued to citicorp holdings inc .", "that were outstanding at december 31 , 2008 and december 31 , 2007 and included in citibank , n.a . 2019s tier 2 capital , amounted to $ 28.2 billion .", "citibank , n.a .", "received an additional $ 14.3 billion in capital contribution from its parent company in january 2009 .", "the impact of this contribution is not reflected in the table above .", "the substantial events in 2008 impacting the capital of citigroup , and the potential future events discussed on page 94 under 201ccitigroup regulatory capital ratios , 201d also affected , or could affect , citibank , n.a. ."], "table": [["in billions of dollars at year end", "2008", "2007"], ["tier 1 capital", "$ 71.0", "$ 82.0"], ["total capital ( tier 1 and tier 2 )", "108.4", "121.6"], ["tier 1 capital ratio", "9.94% ( 9.94 % )", "8.98% ( 8.98 % )"], ["total capital ratio ( tier 1 and tier 2 )", "15.18", "13.33"], ["leverage ratio ( 1 )", "5.82", "6.65"]], "table_ori": [["<i>In billions of dollars at year end</i>", "2008", "2007"], ["Tier 1 Capital", "$71.0", "$82.0"], ["Total Capital (Tier 1 and Tier 2)", "108.4", "121.6"], ["Tier 1 Capital Ratio", "9.94%", "8.98%"], ["Total Capital Ratio (Tier 1 and Tier 2)", "15.18", "13.33"], ["Leverage Ratio<sup>(1</sup><sup>)</sup>", "5.82", "6.65"]]}

Question: what was the change in billions in tier 1 capital from 2007 to 2008?
Evidence:
table_1: in billions of dollars at year end the tier 1 capital of 2008 is $ 71.0 ; the tier 1 capital of 2007 is $ 82.0 ;
Program: subtract(71.0, 82.0)
Answer:
str_answer: -11
exe_answer: -11