Year including construction (constant 2015 US$) 1991 12353.323968772038 1992 14421.36088785016 1993 14205.006566189564 1994 13945.380029865175 1995 14325.23906233951 1996 13416.956393248573 1997 14560.987395791672 1998 14969.582116136171 1999 14784.686345407197 2000 16882.867685853224 2001 18197.9160268509 2002 19216.511330317506 2003 19539.336397920404 2004 18788.7183065675 2005 17334.006422321996 2006 17832.391312486077 2007 17855.741087544662 2008 18216.0536617382 2009 18082.474594317177 2010 16779.645902964014 2011 18573.92876726798 2012 17681.964982079306 2013 18184.43615173278 2014 18151.91322533274 2015 18112.913811825387 2016 17693.45777124194 2017 17560.963018889048 2018 18390.045602421276 2019 17927.489406191093 2020 18030.166469996533 2021 16914.497438487448 2022 17231.212764019354