Year % 2007 6.28 2008 8.04 2009 9.13 2010 9.67 2011 8.95 2012 9.28 2013 7.07 2014 6.69 2015 6.51 2016 5.92 2017 5.95 2018 5.7 2019 5.62 2020 5.07 2021 5.98