The total of the amounts that are payable under sections 15 and 16 in respect of a year shall not exceed:
(a) in the case of the year 1989--$2,213,382,000;
(b) in the case of the year 1990--$2,441,844,000;
(c) in the case of the year 1991--$2,599,025,000;
(d) in the case of the year 1992--$2,733,557,000; and
(e) in the case of the year 1993--$2,943,153,000; and
(f) in the case of the year 1994--$3,520,163,000; and
(g) in the case of the year 1995--$3,652,019,000; and
(h) in the case of the year 1996--$3,803,406,000; and
(i) in the case of the year 1997--$3,855,623,000; and
(j) in the case of the year 1998--$3,857,921,000; and
(k) in the case of the year 1999--$3,459,627,000; and
(l) in the case of the year 2000--$3,425,879,000; and
(m) in the case of the year 2001--$2,756,161,000; and
(n) in the case of the year 2002--$2,847,634,000; and
(o) in the case of the year 2003--$2,904,491,000; and
(p) in the case of the year 2004--$3,010,199,000.