Year % 2005 6.93464044371932 2006 6.48851453820897 2007 6.04732781329616 2008 6.82046607411273 2009 8.51122266859249 2010 5.40141433444005 2011 5.54786930868647 2012 5.50258174332341 2013 6.12922696123063 2014 6.85289678961418 2015 7.29080600484367 2016 7.12062909171045 2017 8.01710711367974 2018 8.30050983901524 2019 8.5879863137146 2020 8.12586633711488 2021 7.70484399222499