Year current US$ 1970 0 1971 0 1972 0 1973 0 1974 90916.157314463 1975 30592.2704322678 1976 15184.5393583076 1977 5773.89892227189 1978 16560.7479889399 1979 515390.597177579 1980 1512688.72026367 1981 449153.784158451 1982 165626.815342951 1983 220799.620024475 1984 64434.4095824197 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 228985.642734618 1998 78553.4896214904 1999 77008.0840506484 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 0 2013 0 2014 0 2015 0 2016 0 2017 0 2018 0 2019 0 2020 0 2021 0