Year % 2007 6.07915470551844 2008 5.04959783379262 2009 4.76133278881495 2010 4.26358624091621 2011 3.64715289300604 2012 3.99955398497272 2013 4.09704120474371 2014 4.35706312340211 2015 5.42519167579409 2016 6.56997239440927 2017 5.48573151051527 2018 7.83653361719762 2019 5.88198439540966 2020 6.14251952164462 2021 6.12052593287218 2022 5.73931420360189