▁highest ▁in comes . ▁( see ▁" F eder al ▁Tax ▁R ate ▁by ▁In come ▁Group " ▁chart ) ▁For ▁those ▁with ▁in comes ▁in ▁the ▁top ▁ 0 . 0 1 ▁percent , ▁overall ▁rates ▁of ▁Federal ▁tax ▁fell ▁from ▁ 7 4 . 6 % ▁in ▁ 1 9 7 0 , ▁to ▁ 3 4 . 7 % ▁in ▁ 2 0 0 4 ▁( the ▁revers al ▁of ▁the ▁tr end ▁in ▁ 2 0 0 0 ▁with ▁a ▁rise ▁to ▁ 4 0 . 8 % ▁came ▁after ▁the ▁ 1 9 9 3 ▁Cl inton ▁def ic it ▁reduction ▁tax ▁bill ), ▁the ▁next ▁ 0 . 0 9 ▁percent ▁falling ▁from ▁ 5 9 . 1 % ▁to ▁ 3 4 . 1 %, ▁before ▁level ing ▁off ▁with ▁a ▁relatively ▁mod est ▁drop ▁of ▁ 4 1 . 4 ▁to ▁ 3 3 . 0 % ▁for ▁the ▁ 9 9 . 5 – 9 9 . 9 ▁percent ▁group . ▁Although ▁the ▁tax ▁rate ▁for ▁low - in come ▁ear ners ▁fell ▁as ▁well ▁( though ▁not ▁as ▁much ), ▁these ▁tax ▁redu ctions ▁compare ▁with ▁virt ually ▁no ▁change ▁– ▁ 2 3 . 3 % ▁tax ▁rate ▁in ▁ 1 9 7 0 , ▁ 2 3 . 4 % ▁in ▁ 2 0 0 4 ▁– ▁for ▁the ▁US ▁population ▁overall . ▁ ▁The ▁study ▁found ▁the ▁decl ine ▁in ▁progress ivity ▁since ▁ 1 9 6 0 ▁was ▁due