Year	current US$
1977	17918518.5185185
1978	32148148.1481481
1979	35611111.1111111
1980	45811111.1111111
1981	52137037.037037
1982	48062962.962963
1983	33548148.1481481
1984	38537037.037037
1985	45662962.962963
1986	55555555.5555556
1987	59448148.1481481
1988	81948148.1481481
1989	107888888.888889
1990	102437037.037037
1991	109311111.111111
1992	128203703.703704
1993	139600000
1994	144403703.703704
1995	135996296.296296
1996	141311111.111111
1997	154707407.407407
1998	160400000
1999	185351851.851852
2000	181740740.740741
2001	170137037.037037
2002	154033333.333333
2003	151259259.259259
2004	160855555.555556
2005	269774074.074074
2006	403003703.703704
2007	334148148.148148
2008	380033333.333333
2009	340940740.740741
2010	348477777.777778
2011	363266666.666667
2012	353896296.296296
2013	308300000
2014	268085185.185185
2015	286929629.62963
2016	367703703.703704