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 .

1	in billions of dollars at year end	2008	2007
2	tier 1 capital	$ 71.0	$ 82.0
3	total capital ( tier 1 and tier 2 )	108.4	121.6
4	tier 1 capital ratio	9.94% ( 9.94 % )	8.98% ( 8.98 % )
5	total capital ratio ( tier 1 and tier 2 )	15.18	13.33
6	leverage ratio ( 1 )	5.82	6.65

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. .

Previous questions in this conversation: what was the tier 2 capital in 2008?
Previous answers: 37.4
Question: and what was it in 2007?
Answer: 39.6