Year US Dollars adjusted for inflation) 1960 168000000 1961 118000000 1962 278000000 1963 201000000 1964 321000000 1965 248000000 1966 341000000 1967 359000000 1968 380000000 1969 405000000 1970 180000000 1971 187000000 1972 627000000 1973 1846000000 1974 1425000000 1975 1125000000 1976 1136000000 1977 1059000000 1978 1782000000 1979 1359000000 1980 2242000000 1981 2573000000 1982 3261000000 1983 3369000000 1984 4535000000 1985 3965000000 1986 3381000000 1987 3464000000 1988 1897000000 1989 1490000000 1990 818000000 2004 74000000 2005 196000000 2006 303000000 2007 297000000 2008 375000000 2009 388000000 2010 439000000 2011 585000000 2012 500000000 2013 375000000 2014 660000000 2015 1471000000 2016 1787000000 2017 943000000 2018 452000000 2019 145000000 2020 4000000 2021 0 2022 55000000