Year	current US$
1960	2000000
1961	2000000
1962	3000000
1963	4000000
1964	2000000
1965	1000000
1966	0
1967	1000000
1968	7000000
1969	6000000
1970	11000000
1971	16000000
1972	18000000
1973	26000000
1974	29000000
1975	20000000
1976	9000000
1977	7000000
1978	13000000
1979	37000000
1980	26000000
1981	40000000
1982	21000000
1983	20000000
1984	18000000
1985	17000000
1986	20000000
1987	19000000
1988	17000000
1989	16000000
1990	21000000
1991	50000000
1992	65000000
1993	62000000
1994	44000000
1995	53000000
1996	38000000
1997	38000000
1998	36000000
1999	38000000
2000	52000000
2001	41000000
2002	39000000
2003	45000000
2004	57000000
2005	83000000
2006	74000000
2007	59000000
2008	65000000
2009	51000000
2010	46000000
2011	56000000
2012	63000000
2013	69000000
2014	99000000
2015	66000000
2016	61000000
2017	21000000
2018	26000000
2019	38000000
2020	22000000
2021	19000000
2022	22000000
2023	27000000