Year constant 2015 US$ 1970 11395.338116381183 1971 11940.616411117911 1972 12172.283202441708 1973 12518.599782992129 1974 12811.430643581942 1975 13415.052312339834 1976 14147.351674789488 1977 14971.471168253975 1978 14677.236309581633 1979 15241.71164719287 1980 15507.333886456352 1981 15500.769999860962 1982 15617.1380564425 1983 15873.760254593291 1984 16334.232208295496 1985 17787.7519966385 1986 18619.371041061062 1987 18418.04426724212 1988 17932.415313320707 1989 17749.40720938899 1990 17810.92785407708 1991 18095.738969874063 1992 18416.95185287214 1993 18723.383819533898 1994 19249.08431670884 1995 19841.13172317826 1996 20989.066563249355 1997 21527.04416673525 1998 22004.577616197883 1999 22670.497459449405 2000 23463.226103616336 2001 23826.361786044745 2002 24441.37335932938 2003 25074.19401841471 2004 26284.793521853906 2005 27255.781324248903 2006 28378.285677026164 2007 29576.677486229943 2008 29700.359120577334 2009 29337.037268691616 2010 30077.67905709795 2011 30392.093007597952 2012 31046.184574823405 2013 31535.344545319625 2014 31827.582099823518 2015 32366.3960767763 2016 32442.90506860257 2017 32902.394660146165 2018 33154.40673039417 2019 33268.07956187193 2020 31015.34146070762 2021 32422.50579768776 2022 34130.951897221574 2023 33502.871427468366