Year including construction (constant 2010 US$) 1991 13433.0987900383 1992 13340.8806366505 1993 12723.6583115932 1994 12279.9814567549 1995 11825.9200043515 1996 11825.8763049854 1997 11836.2881869365 1998 11687.2301149875 1999 11267.3037581168 2000 11534.5728784784 2001 11574.1672660098 2002 12392.7186607266 2003 12819.9871700935 2004 12961.2977758046 2005 13190.3444256386 2006 12653.6076536474 2007 12812.4263258499 2008 12524.1007777676 2009 12167.3291879356 2010 12336.3868242306 2011 12286.5907386879 2012 12120.3987012336 2013 12078.9482620288 2014 11968.8914262101 2015 11568.6248183453 2016 11137.4725786342 2017 11085.9041035556 2018 11490.0867124527