Year	current US$
1960	9000000
1961	8000000
1962	11000000
1963	12000000
1964	13000000
1965	23000000
1966	26000000
1967	31000000
1968	33000000
1969	46000000
1970	57000000
1971	83000000
1972	110000000
1973	166000000
1974	184000000
1975	216000000
1976	209000000
1977	286000000
1978	371000000
1979	538000000
1980	692000000
1981	797000000
1982	689000000
1983	735000000
1984	697000000
1985	580000000
1986	713000000
1987	937000000
1988	1196000000
1989	1500000000
1990	1946000000
1991	1947000000
1992	1861000000
1993	1771000000
1994	1640000000
1995	1911000000
1996	1723000000
1997	2258000000
1998	2251000000
1999	2198000000
2000	2081000000
2001	1809000000
2002	1845000000
2003	2448000000
2004	3231000000
2005	3161000000
2006	3086000000
2007	4067000000
2008	5211000000
2009	4728000000
2010	5657000000
2011	7272000000
2012	8025000000
2013	8352000000
2014	8078000000
2015	7238000000
2016	6143000000
2017	5329000000
2018	6306000000
2019	6564000000
2020	6516000000
2021	8400000000
2022	8087000000
2023	6392000000