Year current US$ 1970 7871332.01650475 1971 8360257.62895302 1972 8445298.85814092 1973 11265883.4453289 1974 11724356.696169 1975 15822130.1386898 1976 16216550.6245017 1977 17734207.3134248 1978 18353355.5692539 1979 27544552.7461731 1980 29585693.9600416 1981 30716610.4776222 1982 25936725.2347262 1983 23327673.2219615 1984 18103018.7033228 1985 24713950.5787521 1986 24417031.289389 1987 29422037.773436 1988 28830869.3683528 1989 28152732.4081878 1990 31202015.6325753 1991 31308901.4958515 1992 32117839.1000402 1993 27721406.6709375 1994 14116426.3559008 1995 17510283.7328538 1996 15571313.2153974 1997 14550128.6343499 1998 14969978.5300914 1999 15689420.1570425 2000 14343345.3260426 2001 14720996.5698448 2002 15754913.5364278 2003 18242436.7064663 2004 20204836.1178879 2005 21375465.99085 2006 20305285.0786792 2007 21958339.6635047 2008 25024497.6990135 2009 25356817.9485614 2010 24750699.063429 2011 28148678.24106 2012 28995504.9260973 2013 19627155.2459245 2014 22016945.6927523 2015 19744122.4179088 2016 21249490.8521789 2017 25046257.1005799 2018 27447570.463942 2019 27439270.4991031 2020 28253062.0665721 2021 30914324.1260583