Year % 2008 7.97505918376389 2009 9.65606140421304 2010 10.70039580593 2011 11.1624793770948 2012 10.8256858254525 2013 10.2542710109923 2014 10.3622692760696 2015 9.7131702028711 2016 9.84390824703115 2017 9.68182103767315 2018 10.181958828354 2019 9.42407147872485 2020 8.17611450836364 2021 8.01734749845187