Year	current US$
1960	5000000
1961	5000000
1962	5000000
1963	5000000
1964	5000000
1965	5000000
1966	6000000
1967	5000000
1968	6000000
1969	8000000
1970	9000000
1971	8000000
1972	8000000
1973	10000000
1974	10000000
1975	11000000
1976	9000000
1977	14000000
1978	18000000
1979	20000000
1980	19000000
1981	17000000
1982	15000000
1983	10000000
1984	12000000
1985	10000000
1986	17000000
1987	14000000
1988	14000000
1989	18000000
1990	21000000
1991	31000000
1992	29000000
1993	32000000
1994	30000000
1995	29000000
1996	22000000
1997	16000000
1998	17000000
1999	38000000
2000	30000000
2001	28000000
2002	31000000
2003	41000000
2004	41000000
2005	50000000
2006	71000000
2007	79000000
2008	114000000
2009	103000000
2010	112000000
2011	134000000
2012	131000000
2013	152000000
2014	170000000
2015	142000000
2016	139000000
2017	147000000
2018	148000000
2019	148000000
2020	138000000
2021	166000000
2022	196000000
2023	186000000