Year including construction (constant 2010 US$) 1991 22535.3097117278 1992 21736.4520255902 1993 21746.2941198457 1994 22094.9062228549 1995 22870.3884033823 1996 22582.8602761672 1997 22442.2608561468 1998 22872.1853509087 1999 22213.3797714769 2000 22514.893287526 2001 20765.3801077294 2002 19624.7699287327 2003 20093.7951582749 2004 20820.464290005 2005 20758.7860029968 2006 21814.3941066506 2007 22869.3751690776 2008 23276.7002559686 2009 22679.2537251527 2010 22073.7611174966 2011 22457.3771272662 2012 22321.9247622505 2013 23610.7674652962 2014 23835.3361022969 2015 23665.6924783307 2016 24336.4571152338 2017 23481.4357611374 2018 23348.365347752