Year	constant 2015 US$
1960	190000
1961	2400000
1962	2850000
1963	3610000
1964	2370000
1965	3440000
1966	4740000
1967	10840000
1968	10640000
1969	10720000
1970	15420000
1971	16300000
1972	24610000
1973	32200000
1974	27130000
1975	23410000
1976	17520000
1977	23840000
1978	33230000
1979	24000000
1980	40040000
1981	32930000
1982	33730000
1983	40010000
1984	29610000
1985	30660000
1986	27520000
1987	31620000
1988	24550000
1989	27440000
1990	28650000
1991	27340000
1992	33820000
1993	21810000
1994	21950000
1995	19330000
1996	16400000
1997	20620000
1998	25090000
1999	26860000
2000	25520000
2001	21940000
2002	31520000
2003	24990000
2004	20580000
2005	30680000
2006	28330000
2007	28430000
2008	26550000
2009	26090000
2010	20790000
2011	51380000
2012	52030000
2013	55060000
2014	70620000
2015	65340000
2016	60840000
2017	74790000