Year	constant 2015 US$
1960	14380630000
1961	14220630000
1962	14997730000
1963	18196240000
1964	20736070000
1965	22016300000
1966	21836570000
1967	23432950000
1968	20540900000
1969	19194650000
1970	20305830000
1971	21233500000
1972	19562900000
1973	23312790000
1974	29736190000
1975	35583310000
1976	33210540000
1977	29819360000
1978	30437770000
1979	30095960000
1980	33807570000
1981	31083890000
1982	30987040000
1983	29289310000
1984	29112190000
1985	31138590000
1986	29153120000
1987	26467330000
1988	27671580000
1989	28918820000
1990	37172110000
1991	38027100000
1992	32760340000
1993	28155890000
1994	30686050000
1995	25719610000
1996	25954530000
1997	23789970000
1998	25786380000
1999	26253080000
2000	25818330000
2001	30032480000
2002	30078100000
2003	27955130000
2004	27505140000
2005	37074830000
2006	41775000000
2007	31261940000
2008	33181670000
2009	38560960000
2010	37419370000
2011	36567090000
2012	37224120000
2013	45923810000
2014	43119630000
2015	43632650000
2016	41810180000
2017	41731560000