Year including construction (constant 2010 US$) 1991 16073.3694636379 1992 15802.1943266763 1993 15479.9059670964 1994 18250.2389011705 1995 19000.0790530727 1996 19180.9750206887 1997 22910.4378657735 1998 23297.1882088489 1999 23744.2437900259 2000 24495.7741505281 2001 24279.21388693 2002 24489.734261072 2003 24964.4667634695 2004 25496.0447054988 2005 25620.100895728 2006 26087.8754710108 2007 27139.9636276732 2008 27062.8274071028 2009 25826.6406309783 2010 27435.3898324115 2011 27662.0154622424 2012 27652.6087428565 2013 27889.5364328516 2014 28155.5518453297 2015 28503.4100372864 2016 29078.956407516 2017 29793.9734866182 2018 24887.0326882075