Not later than the date that is 180 days after April 27, 1998, the Attorney General shall implement a program to collect data, for each fiscal year, regarding the total number of aliens within each of the classes of nonimmigrant aliens described in section
1101
(a)(15) of this title whose authorized period of stay in the United States terminated during the previous fiscal year, but who remained in the United States notwithstanding such termination.