Year current US$ 1980 74.29551043700062 1981 133.275964381249 1982 128.41047134091053 1983 141.34277290455344 1984 115.93973454151273 1985 141.7038260058972 1986 99.04326101129816 1987 134.4991088657013 1988 118.50941454918988 1989 161.0031482790786 1990 181.37192618382704 1991 183.40077731391472 1992 149.02951653803876 1993 160.18777894171058 1994 150.04193871196577 1995 139.0301486981934 1996 150.39044191383337 1997 154.30601157642914 1998 97.15039118389015 1999 129.00381022287428 2000 240.31439087861304 2001 249.43792563361114 2002 260.377071013932 2003 270.94434209695794 2004 311.2150746687023 2005 337.72467988193847 2006 335.5645527355814 2007 369.6825638766452 2008 445.45120269086976 2009 409.01004182489345 2010 425.851151137608 2011 557.6107154847662 2012 462.7989437141858 2013 462.3526084353943 2014 477.9573044490954 2015 454.01910534186123 2016 508.4121002295329 2017 573.5025248279628 2018 641.8009933241088 2019 639.79119602037 2020 610.8568727236997 2021 677.4184155206988