Year per Person 1997 11.94493 1998 12.91152 1999 12.91568 2000 12.97645 2001 13.09366 2002 13.20918 2003 13.25981 2004 13.42281 2005 13.39362 2006 13.44815 2007 13.51484 2008 13.30969 2009 13.10081 2010 12.87329 2011 12.9146 2012 12.75558 2013 12.5525 2014 12.35681 2015 12.16534 2016 11.96749