Year US Dollars adjusted for inflation) 1960 5000000 1961 62000000 1962 3000000 1963 29000000 1964 9000000 1965 18000000 1966 32000000 1967 15000000 1968 32000000 1969 121000000 1970 4000000 1971 36000000 1972 167000000 1973 159000000 1974 1000000 1975 287000000 1976 10000000 1977 8000000 1978 12000000 1979 36000000 1980 12000000 1981 28000000 1982 18000000 1983 303000000 1984 662000000 1985 7000000 1986 6000000 1987 4000000 1988 37000000 1989 218000000 1990 13000000 1991 72000000 1992 36000000 1993 68000000 1994 42000000 1995 35000000 1996 49000000 1997 190000000 1998 162000000 1999 44000000 2000 60000000 2001 268000000 2002 170000000 2003 145000000 2004 18000000 2005 18000000 2006 54000000 2007 226000000 2008 109000000 2009 249000000 2010 261000000 2011 145000000 2012 207000000 2013 171000000 2014 167000000 2015 193000000 2016 18000000 2017 91000000 2018 16000000 2019 22000000 2020 77000000 2021 44000000 2022 44000000