Year % 1994 32.16 1999 17.63 2000 20.15 2001 22.35 2002 20.3 2004 20.29 2005 15.65 2006 15.27 2007 15.24 2008 16.13 2009 16.41 2010 17.09 2011 16.56 2012 17.41 2013 16.39 2014 16.88 2015 16.37 2016 16.74 2018 17.63 2019 18.47 2020 17.3 2021 17.47