Year % 2005 6.17598140010812 2006 6.50537745437133 2007 4.61443076560523 2008 4.43715709395348 2009 5.08878759962213 2010 5.14474111116866 2011 5.07172575956405 2012 6.63041348692 2013 6.74662853927924 2014 6.41862362577497 2015 7.16937013294391 2016 6.50912717272776 2017 7.63271285385605 2018 7.01355268670888 2019 7.63247910791789 2020 7.36972327121168 2021 6.61793895963021