Year	current US$
1960	6000000
1961	6000000
1962	7000000
1963	7000000
1964	9000000
1965	10000000
1966	10000000
1967	10000000
1968	10000000
1969	12000000
1970	16000000
1971	17000000
1972	17000000
1973	16000000
1974	19000000
1975	21000000
1976	19000000
1977	22000000
1978	28000000
1979	22000000
1980	48000000
1981	50000000
1982	47000000
1983	45000000
1984	58000000
1985	55000000
1986	56000000
1987	66000000
1988	88000000
1989	107000000
1990	118000000
1991	110000000
1992	105000000
1993	93000000
1994	96000000
1995	113000000
1996	133000000
1997	135000000
1998	132000000
1999	138000000
2000	148000000
2001	131000000
2002	116000000
2003	128000000
2004	144000000
2005	165000000
2006	167000000
2007	196000000
2008	247000000
2009	225000000
2010	224000000
2011	226000000
2012	208000000
2013	203000000
2014	230000000
2015	214000000
2016	214000000
2017	198000000
2018	302000000
2019	319000000
2020	213000000
2021	230000000
2022	266000000
2023	298000000