Year current US$ 1971 0.022966787979372533 1973 0.45041249412892553 1974 1.5213484774963768 1975 1.1165737485023575 1977 1.3858001790813972 1978 3.1377429942334394 1979 2.5653274705595206 1980 2.82270846627926 1981 3.292661317519012 1982 2.5698939775962355 1983 2.5002583600305366 1984 2.4329663699168576 1986 0.5129228343500318 1987 0.9998225315006586 1988 0.9748745580162472 1990 2.0930621965059815 1992 0.5205207497789088 1993 34.17247895799561 1994 75.47123324185264 1995 68.74124720062535 1996 69.56048037901782 1997 53.89775883610779 1998 72.67668906620463 1999 63.59917585327079 2000 74.39570905037486 2001 115.64112673000906 2002 88.9800826909635 2003 119.45473204281241 2004 95.36975651384729 2005 123.50744711518428 2006 43.814558224823294 2007 43.28869640052964 2008 38.53244024089064 2009 44.29473641828626 2010 51.564191417678224 2011 41.59223451463538 2012 41.80045929893137 2013 24.66654882741934 2014 25.332300997135878 2015 28.11970941637389 2016 19.855661551250815 2017 23.31220616992043 2018 24.450175180914904 2019 76.01138790500993 2020 17.24192275227624 2021 12.139837882187917 2022 14.850576510864373