Year % 1993 14.83 1997 18.14 1998 19.56 2000 13.02 2003 9.36 2005 8.6 2006 8.38 2007 8 2008 8.39 2009 8.52 2010 8.56 2011 7.55 2012 9.49 2013 9.38 2014 9.28 2015 8.35 2016 8.85 2018 7.8 2019 8.11 2020 8.06 2021 7.97