Year constant 2011 international $ 1990 13738.0150384077 1991 13015.6079856328 1992 11486.4735066321 1993 10750.3151577855 1994 9566.07552182136 1995 9338.5903424376 1996 9218.57451133579 1997 9379.21087897455 1998 9100.51823169714 1999 9306.40968514399 2000 10093.1436290836 2001 10497.9147654614 2002 11074.4712682912 2003 11738.1132090272 2004 12756.4226422751 2005 13599.3352038051 2006 14616.8558676577 2007 15770.219597116 2008 16399.2311195969 2009 15377.8425816652 2010 16036.2272770509 2011 16806.2964844318 2012 17330.549715864 2013 17845.136536801 2014 18115.6754120159 2015 18151.3800860718 2016 18306.0215542321 2017 18855.3038152626 2018 19268.6171774216