Year	current US$
1960	6000000
1961	10000000
1962	5000000
1963	8000000
1964	10000000
1965	9000000
1966	9000000
1967	9000000
1968	7000000
1969	9000000
1970	4000000
1971	4000000
1972	6000000
1973	7000000
1974	11000000
1975	21000000
1976	17000000
1977	14000000
1978	16000000
1979	16000000
1980	24000000
1981	22000000
1982	17000000
1983	17000000
1984	19000000
1985	18000000
1986	24000000
1987	27000000
1988	26000000
1989	25000000
1990	28000000
1991	27000000
1992	26000000
1993	27000000
1994	22000000
1995	19000000
1996	22000000
1997	41000000
1998	28000000
1999	28000000
2000	33000000
2001	31000000
2002	39000000
2003	41000000
2004	40000000
2005	34000000
2006	40000000
2007	34000000
2008	51000000
2009	38000000
2010	32000000
2011	45000000
2012	46000000
2013	56000000
2014	57000000
2015	55000000
2016	51000000
2017	50000000
2018	54000000
2019	58000000
2020	52000000
2021	50000000
2022	29000000
2023	24000000