Year	current US$
1960	5000000
1961	5000000
1962	6000000
1963	6000000
1964	7000000
1965	8000000
1966	11000000
1967	11000000
1968	12000000
1969	11000000
1970	13000000
1971	15000000
1972	17000000
1973	18000000
1974	27000000
1975	33000000
1976	30000000
1977	33000000
1978	42000000
1979	70000000
1980	89000000
1981	91000000
1982	71000000
1983	74000000
1984	79000000
1985	83000000
1986	72000000
1987	81000000
1988	98000000
1989	114000000
1990	91000000
1991	112000000
1992	112000000
1993	137000000
1994	139000000
1995	154000000
1996	151000000
1997	158000000
1998	128000000
1999	110000000
2000	92000000
2001	90000000
2002	67000000
2003	94000000
2004	121000000
2005	185000000
2006	217000000
2007	294000000
2008	328000000
2009	268000000
2010	404000000
2011	469000000
2012	486000000
2013	537000000
2014	499000000
2015	466000000
2016	454000000
2017	572000000
2018	601000000
2019	590000000
2020	453000000
2021	526000000
2022	613000000
2023	732000000