Year % 2005 4.91 2007 4.43 2008 4.44 2009 4.44 2011 4.44 2012 3.72 2013 3.83 2014 3.71 2015 3.46 2016 3.63 2017 3.69 2018 3.26 2019 3.52 2020 3.54 2021 3.22