The corporation may make such investigations as it deems necessary to enforce any provision of this subchapter or any rule or regulation thereunder, and may require or permit any person to file with it a statement in writing, under oath or otherwise as the corporation shall determine, as to all the facts and circumstances concerning the matter to be investigated. The corporation shall annually audit a statistically significant number of plans terminating under section
1341
(b) of this title to determine whether participants and beneficiaries have received their benefit commitments and whether section
1350
(a) of this title has been satisfied. Each audit shall include a statistically significant number of participants and beneficiaries.