Year	constant 2015 US$
1961	90000
1963	95630000
1964	38590000
1965	29390000
1966	2810000
1967	2700000
1968	16410000
1969	4700000
1970	3930000
1971	3940000
1972	4480000
1973	4290000
1974	6890000
1975	15440000
1976	25560000
1977	24350000
1978	28830000
1979	31610000
1980	344420000
1981	393740000
1982	496920000
1983	489240000
1984	733840000
1985	565130000
1986	448870000
1987	498590000
1988	423330000
1989	416500000
1990	464790000
1991	518150000
1992	1029710000
1993	679350000
1994	740200000
1995	570200000
1996	440360000
1997	429050000
1998	343710000
1999	301060000
2000	226830000
2001	227210000
2002	266170000
2003	219400000
2004	199440000
2005	394150000
2006	277810000
2007	457740000
2008	584870000
2009	726240000
2010	677870000
2011	651370000
2012	910560000
2013	747060000
2014	682510000
2015	775210000
2016	654250000
2017	717530000