has written commitments from private entities to make qualified contributions having a present value (as of the date of issuance of the issue) of not less than 10 percent of the proceeds of the issue. (c) Limitation on amount of bonds designated (1) National limitation There is a national zone academy bond limitation for each calendar year. Such limitation is $400,000,000 for each of calendar years 2020 through 2029 and, except as provided in paragraph (4), zero thereafter. (2) Allocation of limitation The national zone academy bond limitation for a calendar year shall be allocated by the Secretary among the States on the basis of their respective populations of individuals below the poverty line (as defined by the Office of Management and Budget). The limitation amount allocated to a State under the preceding sentence shall be allocated by the State education agency to qualified zone academies within such State. (3) Designation subject to limitation amount The maximum aggregate face amount of bonds issued during any calendar year which may be designated under subsection (a) with respect to any qualified zone academy shall not exceed the limitation amount allocated to such academy under paragraph (2) for such calendar year. (4) Carryover of unused limitation (A) In general If for any calendar year— (i) the limitation amount for any State, exceeds (ii) the amount of bonds issued during such year which are designated under subsection (a) with respect to qualified zone academies within such State, the limitation amount for such State for the following calendar year shall be increased by the amount of such excess. (B) Limitation on carryover Any carryforward of a limitation amount may be carried only to the first 2 years following the unused limitation year. For purposes of the preceding sentence, a limitation amount shall be treated as used on a first-in first-out basis. (d) Definitions For purposes of this section— (1) Qualified zone academy The term qualified zone academy means any public school (or academic