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 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 4547895.38046107 2011 7563903.98501562 2012 4963218.94870541 2013 4692538.73431453 2014 5407651.98553518 2015 1666473.3511253 2016 1522080.86526333 2017 0 2018 0 2019 0 2020 0 2021 0