in 2017 , the effective rate was lower than the statutory tax rate due to the remeasurement of the deferred tax liabilities as a result of the 2017 tax act . this decrease was partially offset by an increase in the state apportionment impact of the illinois income tax rate change on deferred tax liabilities as well as the reclassification of income tax expense from accumulated other comprehensive income related to the disposal of bm&fbovespa shares