Year including construction (constant 2010 US$) 1991 19709.6002921455 1992 20539.4473517247 1993 21313.2646431847 1994 22537.9812908223 1995 25316.9164426589 1996 27492.5188942062 1997 27238.8797537967 1998 25437.4757389238 1999 26811.5328673575 2000 28271.7651539771 2001 26217.450608543 2002 27527.4862755471 2003 28772.6765727305 2004 31812.5913162875 2005 32335.6934988123 2006 32301.0140325096 2007 33812.7354873053 2008 32754.3756500841 2009 31619.0335794653 2010 31398.7479411389 2011 29348.5198879859 2012 30175.4366784743 2013 30161.3281962113 2014 31443.2888199627 2015 32968.0438616119 2016 33897.369257875 2017 34928.5582833646 2018 35495.747415096