Year including construction (constant 2010 US$) 1991 9062.74414761877 1992 8810.03694241874 1993 8766.05607143761 1994 8724.50458813621 1995 9015.9763874888 1996 9188.11075999941 1997 9563.40970157283 1998 9765.09480034051 1999 10048.5519922225 2000 10561.8743346454 2001 10731.1776021024 2002 11098.5957759238 2003 11518.1343497947 2004 12009.4681779392 2005 12347.5811751655 2006 12953.9782511575 2007 13637.2786224536 2008 14132.3839646281 2009 14293.8564224616 2010 15162.7359677944 2011 15751.7249249325 2012 16080.3071432935 2013 16535.4345961317 2014 16857.7150624746 2015 17121.6678789857 2016 17827.5953505863 2017 18225.9118963527 2018 18696.0085397192