Year including construction (constant 2010 US$) 1991 20685.3105801753 1992 20911.6261451915 1993 20704.2057274254 1994 20966.3156126873 1995 21180.2092972252 1996 21162.2554101511 1997 21870.1835955035 1998 21765.1209172182 1999 21883.6243869377 2000 22094.507775586 2001 21980.215473748 2002 23561.2292022523 2003 24289.5972807698 2004 24541.030644847 2005 25090.7913754467 2006 27796.7176970456 2007 29498.9660224077 2008 27738.6804531667 2009 26718.4012649636 2010 28771.8694757838 2011 28638.6880923153 2012 29352.9623144445 2013 29994.1682115853 2014 29542.0260602188 2015 28309.7000505414 2016 27907.67879606 2017 28084.0578718564 2018 27666.0315249344