Year	constant 2015 US$
1960	4301740000
1961	4676107000
1962	4155099000
1963	4045840000
1964	4663141000
1965	4207773000
1966	4124065000
1967	4100067000
1968	3848514000
1969	4150858000
1970	3815467000
1971	4461533000
1972	4385316000
1973	3962104000
1974	4336928000
1975	4177170000
1976	4361516000
1977	4969154000
1978	5317008000
1979	6189882000
1980	4036117000
1981	4916117000
1982	4307888000
1983	4207558000
1984	4047122000
1985	4251861000
1986	4046485000
1987	3710753000
1988	4554478000
1989	4498383000
1990	3912235000
1991	4487863000
1992	4437214000
1993	4554286000
1994	4834594000
1995	4586568000
1996	4452268000
1997	4465208000
1998	4909957000
1999	4420833000
2000	6084267000
2001	6427591000
2002	6517315000
2003	7428927000
2004	8158058000
2005	10915743000
2006	12114919000
2007	8587550000
2008	10786379000
2009	12073197000
2010	13912330000
2011	13923352000
2012	13932021000
2013	17825509000
2014	17990705000
2015	18544860000
2016	20139408000