Year including construction (constant 2010 US$) 1991 29014.4872228088 1992 28285.9227756696 1993 28237.663454944 1994 28978.7411942558 1995 30057.1167714265 1996 28924.6741050509 1997 32163.03796592 1998 32278.5159002334 1999 33979.5056609193 2000 35208.9834562122 2001 34385.0324000671 2002 37484.309490001 2003 37395.9931343477 2004 35869.1558860635 2005 36918.1289724056 2006 38653.9357838088 2007 39190.2850780054 2008 39758.6414415862 2009 29660.4481334256 2010 35073.5557964393 2011 32602.557653672 2012 30799.8599171891 2013 33922.3716778347 2014 33364.308144302 2015 29739.6391641229 2016 29409.6753346479 2017 27330.9104344481 2018 28631.468024134