Year including construction (constant 2010 US$) 1992 28613.840941314 1993 21654.8264161846 1994 15771.0073902992 1995 13706.4997449184 1996 14305.1418661838 1997 16607.0807945479 1998 19356.749591981 1999 19670.0517637926 2000 17415.5602294836 2001 18407.5811990363 2002 18664.3857916092 2003 18089.6128927045 2004 20789.6673516977 2005 28978.8610742835 2006 41196.8610390191 2007 52331.9382265441 2008 57447.929150353 2009 58746.0973376677 2010 55029.6814423444 2011 49580.6279031001 2012 47438.6774005503 2013 48407.1319083746 2014 47844.8219942145 2015 46735.0674071356 2016 43117.0162291391 2017 40966.0158155912 2018 40488.2392229845