Year % 2000 20.24 2001 20.24 2002 20.23 2003 20.21 2004 20.21 2005 20.22 2006 20.22 2008 20.4 2009 20.4 2010 20.33 2011 20.36 2012 10.1 2013 10.1 2014 10.14 2015 12.95 2016 12.93 2017 12.98 2018 12.97 2019 13.24 2020 12.97 2021 11.44