Year	US Dollars adjusted for inflation)
1968	13000000
1969	13000000
1970	69000000
1971	24000000
1972	26000000
1973	88000000
1974	100000000
1975	153000000
1976	283000000
1977	304000000
1978	217000000
1979	18000000
1980	204000000
1981	429000000
1982	160000000
1983	164000000
1984	312000000
1985	144000000
1986	137000000
1987	199000000
1988	42000000
1989	666000000
1990	564000000
1991	238000000
1992	201000000
1993	578000000
1994	565000000
1995	421000000
1996	480000000
1997	686000000
1998	753000000
1999	436000000
2000	245000000
2001	183000000
2002	221000000
2003	681000000
2004	1145000000
2005	2070000000
2006	1923000000
2007	819000000
2008	728000000
2009	602000000
2010	643000000
2011	1236000000
2012	1137000000
2013	2281000000
2014	733000000
2015	1179000000
2016	941000000
2017	832000000
2018	1136000000
2019	810000000
2020	564000000
2021	508000000
2022	681000000