Year current US$ 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 163724.215767045 1980 1204102.15714679 1981 756707.863345427 1982 602662.195812669 1983 1118348.92231345 1984 861032.712436156 1985 237361.836037318 1986 417912.591628235 1987 168834.956294437 1988 136088.086473785 1989 30814.3709103711 1990 22569.4862864952 1991 181869.267873303 1992 0 1993 0 1994 0 1995 1734841.18411492 1996 1801273.27766956 1997 1045007.20593435 1998 594762.13570557 1999 178962.448850098 2000 71360.3165806798 2001 55063.7927684752 2002 153485.15443492 2003 243311.033434436 2004 629241.883702378 2005 2147598.30643864 2006 9467521.36736025 2007 16764462.40114 2008 1465799.53491526 2009 1715076.37201566 2010 4787229.09193148 2011 10841684.8244302 2012 8800921.0664332 2013 1339693.14190529 2014 916666.856552187 2015 613995.464178826 2016 963569.079638473 2017 928725.011920059 2018 0 2019 0 2020 0 2021 0