Year	current US$
1977	24000000
1978	25592592.5925926
1979	33407407.4074074
1980	46640740.7407407
1981	50596296.2962963
1982	48281481.4814815
1983	55700000
1984	58177777.7777778
1985	60725925.9259259
1986	72525925.9259259
1987	91348148.1481481
1988	106862962.962963
1989	119403703.703704
1990	132370370.37037
1991	131970370.37037
1992	125125925.925926
1993	140781481.481481
1994	143129629.62963
1995	172188888.888889
1996	193277777.777778
1997	196355614.874133
1998	193208022.837652
1999	205461016.572128
2000	248986023.060097
2001	242039076.11315
2002	256537722.908093
2003	256063730.397064
2004	241650074.074074
2005	280128925.925926
2006	320690000
2007	346320111.111111
2008	437002629.629629
2009	367386037.037037
2010	367327185.185185
2011	374276370.37037
2012	351901333.333333
2013	379951703.703704
2014	498004259.259259
2015	518413111.111111
2016	514332407.407407