Year including construction (constant 2010 US$) 1991 27313.1045196596 1992 28915.7768132656 1993 28807.0738790085 1994 29880.3166639401 1995 30496.6736227871 1996 29426.3469099539 1997 29166.2788773666 1998 29633.1546381628 1999 30325.2251490261 2000 29671.7648696627 2001 29741.7472849999 2002 31533.3123891482 2003 33778.8801066098 2004 34391.8680455769 2005 34510.5029929524 2006 36923.1762164432 2007 38072.8338317277 2008 35947.4587570532 2009 33343.2280323026 2010 33591.5977120362 2011 29996.7035892379 2012 27482.7160130857 2013 26482.3684015853 2014 26336.1998817216 2015 27173.007670423 2016 28660.9698896307 2017 31832.919988923 2018 34819.1012348371