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 571500.877889706 1987 1748161.33183834 1988 3041792.48703759 1989 4390762.8832204 1990 18309944.2016015 1991 28959775.0567667 1992 32403909.1536706 1993 37709230.0361967 1994 48499290.3053776 1995 67472712.9132737 1996 49275689.1472174 1997 70651964.9130107 1998 66422059.196194 1999 66335407.7921604 2000 68230282.2763971 2001 58158315.075047 2002 54582074.6207854 2003 63898912.8522945 2004 85222357.7224773 2005 111679263.395976 2006 102290872.140842 2007 37823120.4147045 2008 0 2009 0 2010 0 2011 0 2012 0 2013 0 2014 0 2015 0 2016 0 2017 0 2018 0 2019 0 2020 0 2021 0