Year constant 2011 international $ 1990 31005.636485491 1991 29164.3983210033 1992 27519.3026804507 1993 27090.7660552441 1994 27459.9103809806 1995 28218.5422989711 1996 29017.4330110787 1997 29267.4906697163 1998 30306.2847016489 1999 32088.7824995024 2000 32972.9406359751 2001 33328.0245285838 2002 33668.4424988705 2003 32662.026721545 2004 32354.6996224201 2005 32838.9943043302 2006 33037.6167730227 2007 32884.1288424016 2008 31531.871633751 2009 29703.4249165462 2010 29706.9085147558 2011 29503.7080684624 2012 30079.2030572058 2013 29663.3453617057 2014 29342.5386195132 2015 29366.0597007094 2016 28585.3551325056 2017 28705.2784998865