Year	current US$
1960	18000000
1961	15000000
1962	11000000
1963	13000000
1964	13000000
1965	14000000
1966	10000000
1967	15000000
1968	22000000
1969	27000000
1970	33000000
1971	42000000
1972	36000000
1973	43000000
1974	34000000
1975	32000000
1976	25000000
1977	31000000
1978	27000000
1979	46000000
1980	63000000
1981	34000000
1982	24000000
1983	67000000
1984	167000000
1985	199000000
1986	188000000
1987	260000000
1988	226000000
1989	218000000
1990	288000000
1991	330000000
1992	335000000
1993	384000000
1994	398000000
1995	420000000
1996	528000000
1997	424000000
1998	407000000
1999	422000000
2000	392000000
2001	374000000
2002	448000000
2003	541000000
2004	569000000
2005	578000000
2006	736000000
2007	1047000000
2008	1282000000
2009	1225000000
2010	1282000000
2011	1410000000
2012	1443000000
2013	1982000000
2014	2560000000
2015	1682000000
2016	1774000000
2017	2216000000
2018	3344000000
2019	3052000000
2020	2996000000
2021	3642000000
2022	3568000000
2023	4071000000