Year % 2001 14.23 2002 14.07 2003 14.15 2004 13.9 2005 14.05 2006 12.73 2007 12.47 2008 12.47 2009 12.47 2010 12.51 2011 12.89 2012 12.94 2013 13.11 2014 13.05 2015 10.27 2016 10.39 2017 12.63 2018 12.12 2019 11.48 2020 10.32 2021 10.23