Year including construction (constant 2015 US$) 1991 15663.835830621225 1992 15731.925289905805 1993 16098.673775646614 1994 15321.537193136386 1995 15667.036311117874 1996 16160.271949454953 1997 17900.395117482498 1998 18579.103699001596 1999 18778.681713266993 2000 18079.882166685344 2001 16608.411390964942 2002 16293.646874903028 2003 15279.30832204733 2004 14895.952038375905 2005 15735.322101058317 2006 16085.694024392846 2007 13188.558779062165 2008 13898.346157112275 2009 15137.122532959174 2010 15875.41767108358 2011 15058.832183632065 2012 15610.785860265833 2013 14980.034993964651 2014 15601.554662478451 2015 15569.41658675138 2016 12950.037830532388 2017 13789.646974182488 2018 13180.78621745244 2019 13084.792091547015 2020 12858.508905330238 2021 11958.79807779574 2022 11162.856699092255