Year	constant 2015 US$
1960	515170000
1961	171370000
1962	228250000
1963	197240000
1964	542760000
1965	698970000
1966	356300000
1967	679980000
1968	461160000
1969	563230000
1970	284070000
1971	417840000
1972	870180000
1973	978230000
1974	622680000
1975	648230000
1976	637280000
1977	567240000
1978	655000000
1979	646420000
1980	666220000
1981	820810000
1982	773520000
1983	940980000
1984	837110000
1985	1001110000
1986	1587190000
1987	1131990000
1988	1094960000
1989	1181440000
1990	1739900000
1991	1384400000
1992	2020950000
1993	1738330000
1994	1147670000
1995	957290000
1996	977650000
1997	797600000
1998	764650000
1999	774660000
2000	683340000
2001	723870000
2002	686380000
2003	778860000
2004	485740000
2005	599710000
2006	612090000
2007	616980000
2008	40340000
2009	324580000
2010	512090000
2011	-87410000
2012	47580000
2013	147300000
2014	603740000
2015	525130000
2016	283650000
2017	145500000