Section 3-A. Rate of tax

--    (a) For taxable years ending on or before
  December thirty-first, nineteen hundred  seventy,  the  tax  imposed  by
  section two shall be determined in accordance with the following table:
 
  If the city taxable
      income is:                         The tax is:
  Not over $1,000               0.4% of the city taxable income
  Over $1,000 but not           $4 plus 0.6% of excess over $1,000
    over $3,000
  Over $3,000 but not           $16 plus 0.8% of excess over $3,000
    over $6,000
  Over $6,000 but not           $40 plus 1.0% of excess over $6,000
    over $10,000
  Over $10,000 but not          $80 plus 1.2% of excess over $10,000
    over $15,000
  Over $15,000 but not          $140 plus 1.4% of excess over $15,000
    over $20,000
  Over $20,000 but not          $210 plus 1.6% of excess over $20,000
    over $25,000
  Over $25,000 but not          $290 plus 1.8% of excess over $25,000
    over $30,000
  Over $30,000                  $380 plus 2.0% of excess over $30,000
 
    (b)  For  taxable  years beginning on or after January first, nineteen
  hundred seventy-one and  ending  on  or  before  December  thirty-first,
  nineteen  hundred  seventy-five, and taxable years beginning in nineteen
  hundred seventy-five and ending in nineteen hundred seventy-six, the tax
  imposed by section two  shall  be  determined  in  accordance  with  the
  following table:
 
  If the city taxable
     income is:                         The tax is:
  Not over $1,000               0.7% of the city taxable income
  Over $1,000 but not           $7 plus 1.1% of excess over $1,000
    over $3,000
  Over $3,000 but not           $29 plus 1.4% of excess over $3,000
    over $6,000
  Over $6,000 but not           $71 plus 1.8% of excess over $6,000
    over $10,000
  Over $10,000 but not          $143 plus 2.1% of excess over $10,000
    over $15,000
  Over $15,000 but not          $248 plus 2.5% of excess over $15,000
    over $20,000
  Over $20,000 but not          $373 plus 2.8% of excess over $20,000
    over $25,000
  Over $25,000 but not          $513 plus 3.2% of excess over $25,000
    over $30,000
  Over $30,000                  $673 plus 3.5% of excess over $30,000
 
    (c)  For  each  taxable year beginning in nineteen hundred seventy and
  ending in nineteen hundred seventy-one, two  tentative  taxes  shall  be
  computed,  the  first  as  provided in subdivision (a) and the second as
  provided in subdivision (b), and the tax for each such year shall be the
  sum of that proportion of each tentative tax which the number of days in
  nineteen hundred seventy and the number  of  days  in  nineteen  hundred
  seventy-one,  respectively,  bears  to  the number of days in the entire
  taxable year.