Year % 1996 11.93 1997 12.81 1999 12.13 2000 11.85 2001 11.23 2002 10.26 2003 11.35 2004 11.38 2005 11 2006 12.07 2007 11.64 2008 11.64 2009 11.01 2010 11.03 2011 11.85 2012 9.7 2013 9.66 2014 9.66 2015 10.27 2016 10.5 2017 12.4 2018 12.49 2019 11.29 2020 11.29 2021 11.62