Section 66. Apportionment of costs

1. The total of the several amounts set
  forth in the annual estimate prepared pursuant to section sixty-seven of
  this chapter shall be apportioned to each participant in the  proportion
  that  the  full  valuation  of  its  taxable  real property bears to the
  aggregate full valuation of all participants;  provided,  however,  that
  the rules and regulations adopted pursuant to section sixty-five of this
  chapter may provide that apportionments to a class of participants shall
  be  based  on  a percentage of full valuation rather than on entire full
  valuation.
    2. The full valuation of taxable real property shall be determined  by
  the  use  of  state  equalization  rates established pursuant to article
  two-a of the tax law. The full valuation of a public benefit corporation
  shall be the same as the full valuation of taxable real property of  the
  tax district or districts within which it operates.