Year % 2009 6.83049027589985 2010 5.20416391006098 2011 3.9675616131514 2012 5.43682266670985 2013 6.95249827882881 2014 6.7521584296 2015 6.5941684138 2016 7.18674576794876 2017 8.41730841915147 2018 7.0280449103203 2019 8.44660402666681