Year US Dollars adjusted for inflation) 1964 5000000 1965 10000000 1966 14000000 1967 13000000 1968 23000000 1969 28000000 1970 9000000 1971 21000000 1972 31000000 1973 12000000 1974 45000000 1975 109000000 1976 54000000 1977 195000000 1978 204000000 1979 184000000 1980 264000000 1981 215000000 1982 254000000 1983 409000000 1984 281000000 1985 207000000 1986 347000000 1987 142000000 1988 75000000 1989 209000000 1990 86000000 1991 141000000 1992 300000000 1993 346000000 1994 296000000 1995 154000000 1996 282000000 1997 231000000 1998 215000000 1999 166000000 2000 371000000 2001 441000000 2002 457000000 2003 376000000 2004 579000000 2005 476000000 2006 391000000 2007 558000000 2008 375000000 2009 746000000 2010 644000000 2011 548000000 2012 462000000 2013 410000000 2014 386000000 2015 562000000 2016 1226000000 2017 1187000000 2018 1122000000 2019 348000000 2020 381000000 2021 543000000 2022 831000000