Year	constant 2015 US$
1971	113750000
1972	1111420000
1973	1815780000
1974	2068040000
1975	3760110000
1976	1657680000
1977	2440450000
1978	2702400000
1979	2791370000
1980	2836370000
1981	2486360000
1982	3097870000
1983	2379270000
1984	2783170000
1985	2626420000
1986	2704040000
1987	2931750000
1988	2433340000
1989	2743540000
1990	2924410000
1991	2573440000
1992	2355020000
1993	1815600000
1994	2199920000
1995	1440240000
1996	1444540000
1997	1294050000
1998	1507340000
1999	1572410000
2000	1543270000
2001	1457210000
2002	1205680000
2003	1631340000
2004	1527570000
2005	1386800000
2006	1243930000
2007	1397660000
2008	1865900000
2009	1169500000
2010	1312520000
2011	1312780000
2012	1908330000
2013	2368300000
2014	2190150000
2015	2583930000
2016	2505050000
2017	3745100000