Year including construction (constant 2010 US$) 1991 25854.1001263046 1992 25624.1075572965 1993 26266.3508575188 1994 27415.4711674077 1995 27563.2706281204 1996 28121.5399782877 1997 28238.7035049778 1998 27436.6171467711 1999 26816.9205982669 2000 27097.7306775687 2001 26820.3674094298 2002 26070.6017055273 2003 25839.316000014 2004 26792.2234193369 2005 26492.5353167533 2006 26683.9003510962 2007 26829.2811662842 2008 26803.2031866165 2009 26036.2790990436 2010 27068.0168570228 2011 27875.5705544642 2012 27063.207959002 2013 27349.5842992132 2014 26433.0839865434 2015 23649.2844996329 2016 23704.6806874411 2017 23505.2237140621 2018 23347.4352033132