Year % 2003 11.2 2004 11.2 2005 11.3 2006 11.1 2007 11.6 2008 11.7 2009 12 2010 11.8 2011 11.9 2012 12.1 2013 12 2014 12.2 2015 12 2016 12.3 2017 12.4 2018 12.6 2019 12.8 2020 12.4 2021 12.2