Year	constant 2015 US$
1960	7962020000
1961	8739340000
1962	7784410000
1963	7036930000
1964	6280860000
1965	5320400000
1966	4816480000
1967	3653400000
1968	3346080000
1969	3426180000
1970	5886070000
1971	5417790000
1972	5409060000
1973	10226460000
1974	14687740000
1975	20179190000
1976	20235630000
1977	22225180000
1978	19892350000
1979	20487740000
1980	20288070000
1981	19840060000
1982	16586920000
1983	14714800000
1984	14073360000
1985	15670060000
1986	12877100000
1987	11195900000
1988	8438030000
1989	8524360000
1990	19572850000
1991	18672680000
1992	12771650000
1993	9936860000
1994	11288410000
1995	7089160000
1996	10473940000
1997	7267790000
1998	8167800000
1999	7000740000
2000	6612180000
2001	7096730000
2002	6591820000
2003	10251300000
2004	12214300000
2005	31221900000
2006	18382850000
2007	17787790000
2008	22473910000
2009	13196710000
2010	11700230000
2011	13988810000
2012	12317740000
2013	23210260000
2014	29047490000
2015	24471420000
2016	26107010000
2017	27610880000