Year including construction (constant 2010 US$) 1991 4031.40043900809 1992 3874.74781404156 1993 3747.7413350234 1994 3690.83686519635 1995 3705.88055842233 1996 3717.6772863546 1997 3649.0500576697 1998 3541.69250073353 1999 3341.71150016478 2000 3640.2247943964 2001 4298.88227299792 2002 4923.45008043184 2003 5765.10669225302 2004 6500.15129795789 2005 7295.67640994619 2006 7387.48295157333 2007 7466.65713506329 2008 7279.57048071536 2009 7306.30529677082 2010 7483.13012790046 2011 7681.19272291312 2012 7696.86414398587 2013 7778.97484163073 2014 7849.04777069813 2015 8033.38537921298 2016 8111.52852892658 2017 8061.52159138664 2018 8151.48444806808