Year including construction (constant 2010 US$) 1991 35023.7317039077 1992 35875.2733896738 1993 35297.6154505009 1994 37704.7732203229 1995 34345.0975121938 1996 35115.2318964959 1997 36030.1254629493 1998 33718.7733369004 1999 32539.8063572753 2000 31611.2019753444 2001 31691.1146867586 2002 31833.9354485604 2003 32089.0508132753 2004 32285.434075933 2005 30843.222441896 2006 30780.3159649258 2007 30348.7832575952 2008 30302.0599472872 2009 29374.8926524094 2010 30023.5037264507 2011 30337.0398436136 2012 30491.142856704 2013 29689.6920879032 2014 29577.8366826084 2015 28811.8002527852 2016 27703.9905031813 2017 26834.914564876 2018 26465.5857551811