Year current US$ 1970 0 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 0 2011 0 2012 488664.890380681 2013 272545.80125739 2014 193763.900460229 2015 227295.763104653 2016 62342.0877415217 2017 145065.848217295 2018 8890.77927400493 2019 32751.2754255317 2020 36924.0541738495 2021 58385.7713602088