Year % 1997 11.3989637305699 1998 8.29015544041451 1999 8.29015544041451 2000 8.29015544041451 2001 8.29015544041451 2002 9.06735751295337 2003 9.84455958549223 2004 9.09090909090909 2005 9.09090909090909 2006 10.3626943005181 2007 11.139896373057 2008 11.139896373057 2009 11.139896373057 2010 9.06735751295337 2011 8.80829015544041 2012 8.80829015544041 2013 8.80829015544041 2014 10.0502512562814 2015 10.1010101010101 2016 10.1010101010101 2017 10.0502512562814 2018 12.5628140703518 2019 12.5628140703518 2020 12.0603015075377 2021 13.0653266331658 2022 14.070351758794 2023 14.070351758794