Year	constant 2015 US$
1960	80000
1961	80000
1963	70000
1965	725110000
1966	727440000
1967	809190000
1968	875470000
1969	894000000
1970	1064520000
1971	956190000
1972	1142880000
1973	859410000
1974	970060000
1975	1079450000
1976	809610000
1977	860020000
1978	889420000
1979	794150000
1980	806950000
1981	766340000
1982	725600000
1983	805280000
1984	749540000
1985	702290000
1986	670020000
1987	692010000
1988	677810000
1989	581020000
1990	668300000
1991	630600000
1992	683100000
1993	535100000
1994	525690000
1995	547110000
1996	525320000
1997	517300000
1998	625610000
1999	362030000
2000	483180000
2001	403560000
2002	394780000
2003	358320000
2004	367500000
2005	336080000
2006	341040000
2007	340830000
2008	307750000
2009	418980000
2010	449640000
2011	464440000
2012	521890000
2013	533370000
2014	493870000
2015	592440000
2016	531580000
2017	504410000