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 239011.124363501 2006 469465.974402783 2007 759886.484141165 2008 871815.721779436 2009 1212053.02665098 2010 5420793.24781649 2011 13586706.8778316 2012 14331235.9881796 2013 17438493.8487209 2014 20357149.3255553 2015 5861031.76318257 2016 4654205.30032414 2017 2889952.63350539 2018 4547073.44215067 2019 3394992.30132517 2020 1722691.22834633 2021 4855931.71780001