; and (3) amounts permitted in preceding fiscal years to be obligated pursuant to this subsection that have not been obligated. (b) Excess amounts deposited in escrow account Assessments collected under section 6 in excess of the amount permitted to be obligated under subsection (a) in a fiscal year shall be deposited in an escrow account for the duration of the covered period. (c) Treatment of amounts in escrow account During the covered period, the Board may not obligate, expend, or borrow against amounts required under subsection (b) to be deposited in the escrow account. Any interest earned on such amounts shall be deposited in the escrow account and shall be unavailable for obligation for the duration of the covered period. (d) Release of amounts in escrow account After the covered period, the Board may withdraw and obligate in any fiscal year an amount in the escrow account that does not exceed 1/5 of the amount in the escrow account on the last day of the covered period. (e) Special rule for estimates for particular fiscal years (1) Rule For purposes of subsection (a)(1), the amount of assessments estimated to be collected under section 6 in a fiscal year specified in paragraph (2) shall be equal to 62 percent of the amount of assessments actually collected under such section in the most recent fiscal year for which an audit report has been submitted under section 5(f)(2)(B) as of the beginning of the fiscal year for which the amount that may be obligated is being determined. (2) Fiscal years specified The fiscal years specified in this paragraph are the 9th and 10th fiscal years that begin on or after the date of the enactment of this Act. (f) Covered period defined In this section, the term covered period means the period that begins on the date of the enactment of this Act and ends on the last day of the 11th fiscal year that begins on or after such date of enactment. 17. Study and report by the Government Accountability Office Not later than 5 years and 8 years after the date of enactment of this Act,