interest expense .
what is the increase observed in the interest expense during 2012 and 2013?
2014 vs . 2013 interest incurred decreased $ 9.5 . the decrease was primarily due to a lower average interest rate on the debt portfolio which reduced interest by $ 13 , partially offset by a higher average debt balance which increased interest by $ 6 . the change in capitalized interest was driven by a higher carrying value in construction in progress . 2013 vs . 2012 interest incurred increased $ 13.7 . the increase was driven primarily by a higher average debt balance for $ 41 , partially offset by a lower average interest rate on the debt portfolio of $ 24 . the change in capitalized interest was driven by a decrease in project spending and a lower average interest rate . effective tax rate the effective tax rate equals the income tax provision divided by income from continuing operations before taxes . refer to note 22 , income taxes , to the consolidated financial statements for details on factors affecting the effective tax rate . 2014 vs . 2013 on a gaap basis , the effective tax rate was 27.0% ( 27.0 % ) and 22.8% ( 22.8 % ) in 2014 and 2013 , respectively . the effective tax rate was higher in the current year primarily due to the goodwill impairment charge of $ 305.2 , which was not deductible for tax purposes , and the chilean tax reform enacted in september 2014 which increased income tax expense by $ 20.6 . these impacts were partially offset by an income tax benefit of $ 51.6 associated with losses from transactions and a tax election in a non-u.s . subsidiary . the prior year rate included income tax benefits of $ 73.7 related to the business restructuring and cost reduction plans and $ 3.7 for the advisory costs . refer to note 4 , business restructuring and cost reduction actions ; note 9 , goodwill ; note 22 , income taxes ; and note 23 , supplemental information , to the consolidated financial statements for details on these transactions . on a non-gaap basis , the effective tax rate was 24.0% ( 24.0 % ) and 24.2% ( 24.2 % ) in 2014 and 2013 , respectively . 2013 vs . 2012 on a gaap basis , the effective tax rate was 22.8% ( 22.8 % ) and 21.9% ( 21.9 % ) in 2013 and 2012 , respectively . the effective rate in 2013 includes income tax benefits of $ 73.7 related to the business restructuring and cost reduction plans and $ 3.7 for the advisory costs . the effective rate in 2012 includes income tax benefits of $ 105.0 related to the business restructuring and cost reduction plans , $ 58.3 related to the second quarter spanish tax ruling , and $ 3.7 related to the customer bankruptcy charge , offset by income tax expense of $ 43.8 related to the first quarter spanish tax settlement and $ 31.3 related to the gain on the previously held equity interest in da nanomaterials . refer to note 4 , business restructuring and cost reduction actions ; note 5 , business combinations ; note 22 , income taxes ; and note 23 , supplemental information , to the consolidated financial statements for details on these transactions . on a non-gaap basis , the effective tax rate was 24.2% ( 24.2 % ) in both 2013 and 2012 . discontinued operations during the second quarter of 2012 , the board of directors authorized the sale of our homecare business , which had previously been reported as part of the merchant gases operating segment . in 2012 , we sold the majority of our homecare business to the linde group for sale proceeds of 20ac590 million ( $ 777 ) and recognized a gain of $ 207.4 ( $ 150.3 after-tax , or $ .70 per share ) . in addition , an impairment charge of $ 33.5 ( $ 29.5 after-tax , or $ .14 per share ) was recorded to write down the remaining business , which was primarily in the united kingdom and ireland , to its estimated net realizable value . in 2013 , we recorded an additional charge of $ 18.7 ( $ 13.6 after-tax , or $ .06 per share ) to update our estimate of the net realizable value . in 2014 , a gain of $ 3.9 was recognized for the sale of the remaining homecare business and settlement of contingencies on the sale to the linde group . refer to note 3 , discontinued operations , to the consolidated financial statements for additional details on this business. .