interest expense .
[['', '2019', '2018'], ['interest incurred', '$ 150.5', '$ 150.0'], ['less : capitalized interest', '13.5', '19.5'], ['interest expense', '$ 137.0', '$ 130.5']]
interest incurred increased $ .5 as interest expense associated with financing the lu'an joint venture was mostly offset by favorable impacts from currency , a lower average interest rate on the debt portfolio , and a lower average debt balance .capitalized interest decreased 31% ( 31 % ) , or $ 6.0 , due to a decrease in the carrying value of projects under construction , primarily driven by the lu'an project in asia .other non-operating income ( expense ) , net other non-operating income ( expense ) , net of $ 66.7 increased $ 61.6 , primarily due to lower pension settlement losses , higher non-service pension income , and higher interest income on cash and cash items .the prior year included pension settlement losses of $ 43.7 ( $ 33.2 after-tax , or $ .15 per share ) primarily in connection with the transfer of certain pension assets and payment obligations to an insurer for our u.s .salaried and hourly plans .in fiscal year 2019 , we recognized a pension settlement loss of $ 5.0 ( $ 3.8 after-tax , or $ .02 per share ) associated with the u.s .supplementary pension plan during the second quarter .net income and net income margin net income of $ 1809.4 increased 18% ( 18 % ) , or $ 276.5 , primarily due to impacts from the u.s .tax cuts and jobs act , positive pricing , and favorable volumes .net income margin of 20.3% ( 20.3 % ) increased 310 bp .adjusted ebitda and adjusted ebitda margin adjusted ebitda of $ 3468.0 increased 11% ( 11 % ) , or $ 352.5 , primarily due to positive pricing and higher volumes , partially offset by unfavorable currency .adjusted ebitda margin of 38.9% ( 38.9 % ) increased 400 bp , primarily due to higher volumes , positive pricing , and the india contract modification .the india contract modification contributed 80 bp .effective tax rate the effective tax rate equals the income tax provision divided by income from continuing operations before taxes .the effective tax rate was 21.0% ( 21.0 % ) and 26.0% ( 26.0 % ) in fiscal years 2019 and 2018 , respectively .the current year rate was lower primarily due to impacts related to the enactment of the u.s .tax cuts and jobs act ( the 201ctax act" ) in 2018 , which significantly changed existing u.s .tax laws , including a reduction in the federal corporate income tax rate from 35% ( 35 % ) to 21% ( 21 % ) , a deemed repatriation tax on unremitted foreign earnings , as well as other changes .as a result of the tax act , our income tax provision reflects discrete net income tax costs of $ 43.8 and $ 180.6 in fiscal years 2019 and 2018 , respectively .the current year included a cost of $ 56.2 ( $ .26 per share ) for the reversal of a benefit recorded in 2018 related to the u.s .taxation of deemed foreign dividends .we recorded this reversal based on regulations issued in 2019 .the 2019 reversal was partially offset by a favorable adjustment of $ 12.4 ( $ .06 per share ) that was recorded as we completed our estimates of the impacts of the tax act .this adjustment is primarily related to foreign tax items , including the deemed repatriation tax for foreign tax redeterminations .in addition , the current year rate included a net gain on the exchange of two equity affiliates of $ 29.1 , which was not a taxable transaction .the higher 2018 expense resulting from the tax act was partially offset by a $ 35.7 tax benefit from the restructuring of foreign subsidiaries , a $ 9.1 benefit from a foreign audit settlement agreement , and higher excess tax benefits on share-based compensation .the adjusted effective tax rate was 19.4% ( 19.4 % ) and 18.6% ( 18.6 % ) in fiscal years 2019 and 2018 , respectively .the lower prior year rate was primarily due to the $ 9.1 benefit from a foreign audit settlement agreement and higher excess tax benefits on share-based compensation. .

Question: what is the variation of the effective tax rate considering the years 2018-2019?
Answer: 5.0%
Explanation: it is the difference between those effective tax rates during these years .