Year % 1996 23.76 1999 19.08 2000 13.41 2001 12.19 2002 13.63 2003 13.82 2006 13.79 2007 13.74 2008 15.46 2009 15.62 2010 14.96 2011 14.11 2012 13.5 2013 13.5 2014 14.29 2015 14.29 2016 14.29 2017 15.38 2018 15.58 2019 17.12 2020 10.13