Year including construction (constant 2010 US$) 1991 30664.802617477 1992 31326.7571965368 1993 32800.4769537746 1994 34802.1655431506 1995 37070.3907308037 1996 38948.0831623858 1997 39786.0162721894 1998 43545.9744343392 1999 49266.8595398534 2000 50736.5866104846 2001 50160.1394778719 2002 49756.0650022688 2003 50047.0721383725 2004 50144.7920458005 2005 50362.2643863989 2006 49851.8270231689 2007 48126.1809224542 2008 46930.0673989918 2009 46695.2522560949 2010 45936.4513420071 2011 44322.7842982453 2012 44654.6713059317 2013 45572.5727451671 2014 45971.1115251323 2015 45974.6204178029 2016 45846.0530174752 2017 45419.5912270837 2018 46622.9955998458