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 23425.559600384 2006 38601.2975484078 2007 0 2008 0 2009 0 2010 0 2011 0 2012 70053.0965689347 2013 395187.684828138 2014 227150.244276539 2015 229299.605395349 2016 173530.775186534 2017 235387.857113411 2018 294630.708214813 2019 454083.983883907 2020 122328.077965982 2021 156063.797056492