Year	current US$
1960	12000000
1961	6000000
1962	7000000
1963	4000000
1964	7000000
1965	6000000
1966	6000000
1967	7000000
1968	7000000
1969	11000000
1970	16000000
1971	20000000
1972	24000000
1973	34000000
1974	34000000
1975	40000000
1976	30000000
1977	38000000
1978	53000000
1979	53000000
1980	68000000
1981	71000000
1982	72000000
1983	87000000
1984	83000000
1985	84000000
1986	107000000
1987	100000000
1988	106000000
1989	112000000
1990	136000000
1991	147000000
1992	180000000
1993	154000000
1994	209000000
1995	252000000
1996	234000000
1997	235000000
1998	228000000
1999	246000000
2000	230000000
2001	234000000
2002	276000000
2003	351000000
2004	431000000
2005	438000000
2006	542000000
2007	750000000
2008	825000000
2009	709000000
2010	742000000
2011	947000000
2012	766000000
2013	725000000
2014	768000000
2015	604000000
2016	666000000
2017	789000000
2018	816000000
2019	796000000
2020	720000000
2021	821000000
2022	910000000
2023	980000000