Year % 2007 10.9439642806736 2008 9.91289346522696 2009 10.2105954684001 2010 11.4926070127833 2011 11.3282656125364 2012 11.0384460809472 2013 11.0653864675177 2014 10.2747346709378 2015 10.8346723535516 2016 11.4566913733892 2017 11.4387899664859 2018 11.6028591501557 2019 11.1880133317311 2020 11.7680557546601 2021 12.1811662512738