Year % 1993 17.77 1998 12.6 1999 13.03 2000 13.4 2001 13.09 2002 13.43 2003 14.52 2004 15.46 2005 13.47 2006 13.59 2007 14.07 2008 14.15 2009 14.52 2010 13.66 2011 14.62 2012 13.79 2013 14.24 2014 15.11 2015 15.08 2016 15.03 2017 15.16 2018 13.47 2019 13.39 2020 12.79 2021 13.21