Year including construction (constant 2010 US$) 1991 18885.0616323866 1992 19107.5814331736 1993 19296.8430173087 1994 18528.7225228728 1995 18532.6665603726 1996 18727.7885264241 1997 19613.9348941521 1998 21119.7717587013 1999 22755.9623576636 2000 23823.4566665627 2001 23343.6781957916 2002 23429.8473921953 2003 22489.716577548 2004 22868.4420329632 2005 22475.8792791102 2006 22219.9087808004 2007 22585.5772131412 2008 23062.4530505576 2009 22521.2808654858 2010 22711.4013194119 2011 23252.5805669137 2012 21534.2500931504 2013 20958.5777253583 2014 21419.4095406223 2015 21579.4251552459 2016 24087.2387889225 2017 23755.2240299222