<prompt> Translate the following text to EnglishHii ni kwa sababu ya ongezeko la viwango vya kodi, na sio kupunguzwa kwa viwango vya kodi, kama ilivyoelezwa katika Sheria ya Marekebisho ya Usalama wa Jamii ya 1983.  <response>: This was mainly the result of rate hikes-- not cuts--legislated in the Social Security Reform act of 1983. 