The taxes imposed under this subchapter , less the credits allowed under section 422.12 , shall be reduced by a tax credit authorized pursuant to section 15E.66 , if redeemed, for investments in the Iowa fund of funds. 2006 Acts, ch 1158, §20 ; 2007 Acts, ch 161, §18, 22 ; 2020 Acts, ch 1062, §94 Referred to in §422.16