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 11.85 2007 11.39 2008 11.39 2009 10.73 2010 10.81 2011 11.65 2012 9.54 2013 9.52 2014 9.51 2015 9.31 2016 9.3 2017 12.4 2018 11.73 2019 10.01 2020 10.01 2021 10.39