Year	current US$
1960	3000000
1961	5000000
1962	4000000
1963	5000000
1964	6000000
1965	7000000
1966	7000000
1967	7000000
1968	6000000
1969	8000000
1970	9000000
1971	6000000
1972	8000000
1973	10000000
1974	16000000
1975	17000000
1976	21000000
1977	25000000
1978	29000000
1979	36000000
1980	58000000
1981	46000000
1982	46000000
1983	55000000
1984	49000000
1985	57000000
1986	87000000
1987	79000000
1988	115000000
1989	109000000
1990	127000000
1991	110000000
1992	123000000
1993	120000000
1994	106000000
1995	109000000
1996	80000000
1997	61000000
1998	62000000
1999	56000000
2000	43000000
2001	44000000
2002	44000000
2003	62000000
2004	80000000
2005	64000000
2006	94000000
2007	98000000
2008	164000000
2009	166000000
2010	215000000
2011	160000000
2012	182000000
2013	174000000
2014	161000000
2015	180000000
2016	120000000
2017	127000000
2018	62000000
2019	82000000
2020	55000000
2021	59000000
2022	79000000
2023	77000000