Year % 2006 10.8 2007 11.4 2008 11.7 2009 11.8 2010 11.8 2011 11.6 2012 11.5 2013 11.4 2014 11.9 2015 11.8 2016 12.1 2017 11.7 2018 11.9 2019 12.1 2020 12.3 2021 12.5