Year % 2008 5.45350630049101 2009 6.23096466231012 2010 6.78389119750208 2011 6.83583959729123 2012 7.4369887255935 2013 7.55530675097008 2014 7.16761401120425 2015 7.12183209283378 2016 7.64707124159309 2017 8.19395489709604 2018 7.91208376467566 2019 8.0079591051095 2020 7.61014587740305 2021 8.09058344861373