Pub. L. 110–234 and Pub. L. 110–246 made identical amendments to this section. The amendments by Pub. L. 110–234 were repealed by section 4(a) of Pub. L. 110–246.

2018—Subsec. (c)(2). Pub. L. 115–334 substituted “2023” for “2018”.

2014—Subsec. (c). Pub. L. 113–79 amended subsec. (c) generally. Prior to amendment, text read as follows: “There are authorized to be appropriated such sums as are necessary to carry out this section for each of fiscal years 1999 through 2012.”

2008—Subsec. (c). Pub. L. 110–246, § 7131, substituted “2012” for “2007”.

2002—Subsec. (c). Pub. L. 107–171 substituted “2007” for “2002”.

Amendment of this section and repeal of Pub. L. 110–234 by Pub. L. 110–246 effective May 22, 2008, the date of enactment of Pub. L. 110–234, see section 4 of Pub. L. 110–246, set out as an Effective Date note under section 8701 of this title.