Year current US$ 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 0 1996 0 1997 0 1998 0 1999 0 2000 0 2001 0 2002 2827093.58730489 2003 4067063.68150124 2004 7072806.66060776 2005 16412097.2062937 2006 24764330.1497468 2007 36727846.7334896 2008 41847154.6454129 2009 10389025.9427227 2010 0 2011 0 2012 26111470.4907643 2013 25014697.5684794 2014 22923321.2794536 2015 9599630.09717278 2016 7795049.60214203 2017 2889952.63350539 2018 4547073.44215067 2019 3394992.30132517 2020 1722691.22834633 2021 4855931.71780001