At the beginning of each fiscal year in which the pilot program under this section is in effect, each State that does not intend to use the allotment to which it is entitled for such year (or any allotment which was made to it for a prior fiscal year), or that does not intend to use the full amount of any such allotment, shall certify to the Commissioner of Social Security the amount of such allotment which it does not intend to use, and the State’s allotment for the fiscal year (or years) involved shall thereupon be reduced by the amount so certified.