Year including construction (constant 2010 US$) 1991 20559.7253184498 1992 19686.4986356496 1993 19447.2567402284 1994 21562.2619079358 1995 21175.2258794706 1996 5852.9247160603 1997 5920.51285715109 1998 6870.19983140153 1999 6948.9732168137 2000 8354.45844762766 2001 9031.74661945551 2002 9536.85845955835 2003 10065.3827320822 2004 9902.5686150538 2005 9966.74530731195 2006 10324.915068571 2007 10832.3591806807 2008 10810.1606121648 2009 11165.4281557332 2010 11918.9734832498 2011 13482.3221577143 2012 13617.8112663684 2013 14203.473309795 2014 14362.7424520872 2015 14712.035451992 2016 15407.4941196033 2017 15304.9905441356 2018 15577.9444009866