Year constant 2015 US$ 1975 6173.28955078125 1976 7484.796875 1977 8708.41015625 1978 9350.9462890625 1979 10197.6142578125 1980 10667.7890625 1981 10756.20703125 1982 11269.7626953125 1983 11801.1376953125 1984 12669.4365234375 1985 13127.466796875 1986 13458.462890625 1987 14253.4912109375 1988 15322.615234375 1989 16306.251953125 1990 17144.388671875 1991 16829.833984375 1992 17928.45703125 1993 17623.201171875 1994 18280.935546875 1995 19453.755859375 1996 19385.203125 1997 19617.09375 1998 20562.1953125 1999 21349.64453125 2000 22383.857421875 2001 23019.138671875 2002 23604.0703125 2003 23930.66015625 2004 24799.537109375 2005 25631.255859375 2006 26395.400390625 2007 27156.671875 2008 27449.03125 2009 26183.451171875 2010 26090.037109375 2011 25538.771484375 2012 24285.486328125 2013 22738.48046875 2014 22581.81640625 2015 23487.21875 2016 24916.619140625 2017 26101.28515625 2018 27241.064453125 2019 28362.083984375 2020 27076.740234375 2021 29484.400390625 2022 30556.71875 2023 30768.919921875