Year % 2002 20.23 2003 20.32 2005 19.74 2006 15.89 2007 14.1 2008 13.59 2009 14.91 2010 14.91 2011 11.67 2012 10.73 2013 10.76 2014 10.52 2015 8.86 2016 9.02 2018 10.36 2019 8.07 2020 10.77 2021 10.86