Year current US$ 1970 1668857.53754713 1971 801639.595386032 1972 871298.343903054 1973 1084836.55505354 1974 1349201.66107009 1975 1496753.82705718 1976 1239082.92699963 1977 1886715.07954309 1978 2117194.77358721 1979 2441606.26779078 1980 2976968.90730188 1981 3588374.39418696 1982 3816094.7379683 1983 3883222.19888313 1984 4136465.25803659 1985 4796644.83363058 1986 5078209.53888915 1987 5475361.22853228 1988 5927344.95508511 1989 6687033.2899047 1990 8093791.25442655 1991 7841521.34186855 1992 7924565.48791149 1993 8812399.29848775 1994 9150321.82599013 1995 9604496.70340766 1996 10423194.0147089 1997 11592210.3366629 1998 13760150.2261583 1999 15783484.400303 2000 14346682.450605 2001 19903631.0760284 2002 21712085.0591638 2003 23936490.9771415 2004 28744907.616749 2005 32874066.6415882 2006 39173316.4815528 2007 53238109.831061 2008 63583894.0142755 2009 78254376.646222 2010 102424457.278886 2011 119603837.436193 2012 130852693.520913 2013 135828366.224346 2014 133462064.386087 2015 121066487.371091 2016 132248319.434959 2017 139130584.99698 2018 144714737.781652 2019 149707421.806697 2020 144059024.796259 2021 149979332.793955