Year	current US$
1960	8000000
1961	8000000
1962	9000000
1963	11000000
1964	10000000
1965	13000000
1966	15000000
1967	13000000
1968	12000000
1969	14000000
1970	14000000
1971	19000000
1972	22000000
1973	31000000
1974	92000000
1975	87000000
1976	86000000
1977	92000000
1978	102000000
1979	165000000
1980	186000000
1981	186000000
1982	172000000
1983	181000000
1984	169000000
1985	174000000
1986	260000000
1987	346000000
1988	391000000
1989	418000000
1990	452000000
1991	341000000
1992	333000000
1993	313000000
1994	285000000
1995	371000000
1996	369000000
1997	293000000
1998	255000000
1999	277000000
2000	273000000
2001	268000000
2002	303000000
2003	347000000
2004	381000000
2005	402000000
2006	396000000
2007	431000000
2008	487000000
2009	360000000
2010	380000000
2011	491000000
2012	475000000
2013	542000000
2014	559000000
2015	406000000
2016	575000000
2017	596000000
2018	699000000
2019	826000000
2020	816000000
2021	802000000
2022	832000000
2023	908000000