Year constant 2015 US$ 1970 5633.349872962452 1971 5752.682010428397 1972 6171.123206328656 1973 6424.203215860025 1974 6711.270495948224 1975 6558.857314553684 1976 6729.180102511758 1977 6913.748150593184 1978 7345.106315777376 1979 7731.546647488781 1980 7270.8240236346355 1981 8056.549426739471 1982 8553.96148312481 1983 9132.086740889661 1984 8395.53516345812 1985 8354.71392679941 1986 9467.732794940901 1987 10145.447032498932 1988 10445.758674410426 1989 10326.475411334393 1990 10609.368244244873 1991 10714.012033846835 1992 11134.683601716057 1993 11623.860281235973 1994 12409.476035671478 1995 13102.530337850761 1996 13517.596571399286 1997 13714.46136069359 1998 14181.06835152692 1999 14414.681570171075 2000 15204.012164556292 2001 15428.405381455203 2002 15355.79279771952 2003 15118.565514801667 2004 15629.624232888977 2005 15883.115824954522 2006 16411.791778296036 2007 17330.28176841279 2008 17393.394876715316 2009 17161.95760497179 2010 17664.761612127717 2011 18084.226789385782 2012 18226.785376527925 2013 18475.321018568557 2014 18840.69205219738 2015 19151.058449765962 2016 19930.254181124987 2017 20241.80140846074 2018 20563.47086562667 2019 20983.18807478729 2020 19090.391334427637 2021 20923.987300296183 2022 22037.400825021883 2023 21429.232829088767