Section 936. Return of unpaid delinquent taxes

1. Upon the expiration of
  his warrant, each collecting officer  shall  make  and  deliver  to  the
  county  treasurer  an  account,  subscribed  and affirmed by him as true
  under the penalties of perjury, of all taxes  listed  on  the  tax  roll
  which  remain  unpaid,  except  that  such  collecting officer shall not
  include in such account the amount of the installments of taxes returned
  unpaid pursuant to section nine hundred  twenty-eight-b  or  subdivision
  one  of  section  nine  hundred  seventy-six of this chapter. The county
  treasurer shall, if satisfied that such account is correct,  credit  him
  with  the  amount  of such unpaid delinquent taxes. Such return shall be
  endorsed upon or attached to the tax roll.
    2. In making the return of unpaid taxes, the collecting officer  shall
  add  five  per  centum to the amount of each tax as levied. In the event
  that the collecting officer fails to do so, the county  treasurer  shall
  make  such addition. In a county in which there is a local law in effect
  pursuant to section nine hundred twenty-eight-b or section nine  hundred
  seventy-two  of  this  chapter  providing for the collection of taxes in
  installments, the five per centum provided by this subdivision shall not
  be added to the taxes which a real property owner has elected to pay  in
  installments  pursuant to section nine hundred twenty-eight-b or section
  nine hundred seventy-five of this chapter. Such five per centum shall be
  added by the county treasurer to the amount of such taxes as shall  have
  remained  unpaid  after the date upon which the last installment was due
  as provided in such local law. The amount of such added per centum shall
  thereafter be deemed part of the amount of the unpaid tax.