Year % 2007 5.08 2008 5.08 2009 5.05 2010 5.15 2011 5.5 2012 5.47 2013 3.7 2014 3.73 2015 3.42 2016 3.14 2017 3.11 2018 2.99 2019 2.92 2020 2.95 2021 3.01