Year	current US$
1970	87000000
1971	80000000
1972	90000000
1973	106000000
1974	136000000
1975	144000000
1976	170000000
1977	232000000
1978	372000000
1979	389000000
1980	418000000
1981	383000000
1982	615000000
1983	187000000
1984	208000000
1985	217000000
1986	185000000
1987	215000000
1988	211000000
1989	368000000
1990	701000000
1991	677000000
1992	858000000
1993	729000000
1994	609000000
1995	203000000
1996	290000000
1997	211000000
1998	261000000
1999	195000000
2000	331000000
2001	406000000
2002	383000000
2003	209000000
2004	214000000
2005	211000000
2006	257000000
2007	662000000
2008	841000000
2009	582000000
2010	805000000
2011	782000000
2012	899000000
2013	1117000000
2014	193000000
2015	105000000
2016	54000000