Year including construction (constant 2010 US$) 1991 6052.09063908579 1992 5705.75600510911 1993 5331.34582359394 1994 4644.16668547035 1995 4267.21803761012 1996 4801.32467179052 1997 5155.75847677436 1998 5501.47161059957 1999 5822.10935172393 2000 6042.45499624315 2001 6250.5874965199 2002 6613.8130747938 2003 7207.24968109563 2004 8423.48011055117 2005 9427.3084948887 2006 10600.4627247962 2007 11417.8723313251 2008 12996.4035365285 2009 12966.5469120299 2010 14452.8704282929 2011 15575.2424407248 2012 15867.1449105511 2013 15476.9222768053 2014 15711.6999167729 2015 14668.0902440458 2016 13793.8118381482 2017 14713.3266352137 2018 15598.6971864053