This part was added as part E of title IV of Pub. L. 89–329 by Pub. L. 92–318, title I, § 137(b), June 23, 1972, 86 Stat. 273, and amended by Pub. L. 94–482, Oct. 12, 1976, 90 Stat. 2081; Pub. L. 95–43, June 15, 1977, 91 Stat. 213; Pub. L. 95–561, Nov. 1, 1978, 92 Stat. 2143; Pub. L. 96–49, Aug. 13, 1979, 93 Stat. 351; Pub. L. 96–374, Oct. 3, 1980, 94 Stat. 1367; Pub. L. 97–35, Aug. 13, 1981, 95 Stat. 357; Pub. L. 97–301, Oct. 13, 1982, 96 Stat. 1400; Pub. L. 98–79, Aug. 15, 1983, 97 Stat. 476; Pub. L. 99–272, Apr. 7, 1986, 100 Stat. 82. Such part is shown herein, however, as having been added by Pub. L. 99–498, title IV, § 405(a), Oct. 17, 1986, 100 Stat. 1439, without reference to such intervening amendments because of the extensive revision of this part by Pub. L. 99–498. The letter designation of this part was changed from “E” to “D” for codification purposes. See Codification note preceding section 1087a of this title.