Year constant 2015 US$ 1970 11808.506457858055 1971 12187.585119727915 1972 13184.731395039542 1973 13825.735631022962 1974 12847.5826564382 1975 13324.112928431025 1976 13421.351331379274 1977 13921.890056728684 1978 14463.15917987221 1979 14334.449394776473 1980 13976.440062609341 1981 14196.578271895261 1982 14234.416139524106 1983 14176.303213781383 1984 14337.573738856867 1985 14583.88597362727 1986 14981.070052769881 1987 15432.646660441713 1988 15977.353640339383 1989 16852.75671678668 1990 17962.084813559355 1991 17929.304869781987 1992 18020.451718837085 1993 18794.17659074895 1994 19647.009896171254 1995 21086.659569127867 1996 22476.30111509505 1997 24377.263656273135 1998 26389.95769361447 1999 27728.024214183348 2000 30079.116957610535 2001 30803.75192234969 2002 31377.11985464651 2003 32417.39471504617 2004 32704.84906179045 2005 33742.26177938836 2006 34260.1719455635 2007 34628.911757450165 2008 32650.20035568786 2009 29431.351530658303 2010 29721.314257172467 2011 29185.977351105288 2012 28943.748642642924 2013 30609.352219944165 2014 32777.06461126452 2015 34222.82991613407 2016 35733.15809907135 2017 36360.76574120614 2018 37290.13128124785 2019 38641.75731448292 2020 36121.903337209056 2021 42024.464501221606