Year % 2001 13.25 2002 12.62 2003 12.33 2004 11.5 2005 12.01 2006 9.21 2007 8.7 2008 8.7 2009 8.7 2010 10.15 2011 9.34 2012 8.59 2013 9.24 2014 8.34 2015 7.33 2016 7.16 2017 9.44 2018 8.77 2019 7.72 2020 7.18 2021 7.64