Year	current US$
1960	4000000
1961	4000000
1962	4000000
1963	5000000
1964	6000000
1965	7000000
1966	7000000
1967	7000000
1968	7000000
1969	8000000
1970	9000000
1971	10000000
1972	12000000
1973	15000000
1974	26000000
1975	23000000
1976	13000000
1977	16000000
1978	19000000
1979	29000000
1980	29000000
1981	32000000
1982	33000000
1983	34000000
1984	43000000
1985	36000000
1986	37000000
1987	52000000
1988	53000000
1989	43000000
1990	52000000
1991	58000000
1992	69000000
1993	59000000
1994	53000000
1995	63000000
1996	57000000
1997	55000000
1998	54000000
1999	55000000
2000	43000000
2001	51000000
2002	53000000
2003	70000000
2004	86000000
2005	99000000
2006	115000000
2007	138000000
2008	180000000
2009	210000000
2010	233000000
2011	277000000
2012	273000000
2013	284000000
2014	278000000
2015	214000000
2016	219000000
2017	253000000
2018	243000000
2019	265000000
2020	280000000
2021	327000000
2022	348000000
2023	375000000
