Year	current US$
1960	8000000
1961	9000000
1962	11000000
1963	17000000
1964	13000000
1965	15000000
1966	20000000
1967	27000000
1968	30000000
1969	28000000
1970	125000000
1971	127000000
1972	199000000
1973	67000000
1974	83000000
1975	50000000
1976	65000000
1977	81000000
1978	104000000
1979	125000000
1980	127000000
1981	199000000
1982	187000000
1983	177000000
1984	212000000
1985	201000000
1986	254000000
1987	288000000
1988	368000000
1989	308000000
1990	311000000
1991	327000000
1992	316000000
1993	481000000
1994	252000000
1995	272000000
1996	313000000
1997	424000000
1998	415000000
1999	345000000
2000	346000000
2001	318000000
2002	388000000
2003	460000000
2004	446000000
2005	374000000
2006	439000000
2007	331000000
2008	337000000
2009	484000000
2010	320000000
2011	300000000
2012	422000000
2013	388000000
2014	346000000
2015	379000000
2016	388000000
2017	397000000
2018	377000000
2019	353000000
2020	409000000
2021	310000000
2022	377000000
2023	379000000