Year current US$ 1970 4162.113913377702 1971 4508.968476240521 1972 5296.0444986603425 1973 6413.205134213928 1974 7050.944973378873 1975 8849.708765193336 1976 9468.32595677854 1977 9859.674543992152 1978 10825.374688420801 1979 12757.26197956974 1980 14680.603383412563 1981 13275.500183253223 1982 11593.428609099616 1983 10583.844633165001 1984 11050.520770037683 1985 11509.613443747701 1986 15273.82606029275 1987 18595.27996153792 1988 20852.66061919834 1989 21697.038439042954 1990 25680.582584909513 1991 26549.294041137353 1992 26897.011803852114 1993 19711.194006764876 1994 21623.408110878405 1995 25357.171908753306 1996 27555.750884238296 1997 25246.407112049747 1998 25552.046732452836 1999 26206.53854074454 2000 25025.380673076266 2001 22859.30562827542 2002 25085.752411421992 2003 31984.25532137044 2004 36331.38474370356 2005 37127.98038178709 2006 40452.40966429753 2007 46849.53731377177 2008 48848.586775591706 2009 39718.794797179224 2010 45188.85552974133 2011 51652.818109281056 2012 49429.39236991907 2013 52089.635275940775 2014 51104.43076524678 2015 43373.545425610966 2016 43610.18669700501 2017 45639.9405617351 2018 46269.20866664426 2019 44558.12293406543 2020 45322.00706985667 2021 51830.62661457461