Year including construction (constant 2010 US$) 1991 14768.8736581768 1992 16739.1988812764 1993 16833.5512688831 1994 16817.5903295957 1995 15890.886056526 1996 14723.0209650235 1997 15226.3772788447 1998 15093.2404492326 1999 15884.7150173759 2000 16261.5268297262 2001 17573.0356023038 2002 19993.9764757093 2003 18128.0749128449 2004 17920.458004783 2005 18657.5771211627 2006 19586.6027282603 2007 19426.5022900088 2008 20061.3801511828 2009 18548.0707874507 2010 18309.8020416544 2011 18423.0828697354 2012 17870.9377533464 2013 17729.9413798862 2014 17408.5649085095 2015 17366.8549530477 2016 17428.7727734141 2017 17128.0782801776 2018 16973.0547262686