Year	current US$
1960	2000000
1961	2000000
1962	2000000
1963	2000000
1964	2000000
1965	2000000
1966	4000000
1967	5000000
1968	6000000
1969	7000000
1970	10000000
1971	15000000
1972	21000000
1973	25000000
1974	28000000
1975	32000000
1976	39000000
1977	46000000
1978	58000000
1979	85000000
1980	99000000
1981	93000000
1982	98000000
1983	88000000
1984	88000000
1985	99000000
1986	106000000
1987	113000000
1988	159000000
1989	165000000
1990	186000000
1991	172000000
1992	192000000
1993	238000000
1994	206000000
1995	233000000
1996	379000000
1997	340000000
1998	384000000
1999	434000000
2000	342000000
2001	476000000
2002	420000000
2003	412000000
2004	497000000
2005	675000000
2006	757000000
2007	859000000
2008	1087000000
2009	794000000
2010	984000000
2011	1049000000
2012	1071000000
2013	1082000000
2014	1144000000
2015	991000000
2016	1040000000
2017	1302000000
2018	1271000000
2019	1167000000
2020	1004000000
2021	1133000000
2022	1364000000
2023	1431000000