Year including construction (constant 2015 US$) 1991 6321.784027642654 1992 6257.133820069166 1993 5979.0880253817695 1994 5717.222244379645 1995 5655.710518664839 1996 5892.122501038848 1997 5905.626399177741 1998 5811.359643907179 1999 5799.191032498545 2000 5622.299227155011 2001 5537.910762246429 2002 5453.263436682233 2003 5557.496802429796 2004 5750.165908424717 2005 5863.744863908322 2006 5922.185063179192 2007 5932.447071753923 2008 6143.902353530327 2009 6087.522586330203 2010 6273.957163287902 2011 6380.458096315256 2012 6147.915131339289 2013 6081.188329139809 2014 6270.933719059386 2015 6154.103798021941 2016 6191.808302107054 2017 6363.905674910109 2018 6511.388414691882 2019 6598.337301509443 2020 6346.1995246791175 2021 6362.661785903633 2022 6416.218603873254