Year % 2009 3.29242857718552 2010 2.76498233309994 2011 2.80757714682396 2012 3.63707898309436 2013 4.15037241131952 2014 4.91975055211583 2015 7.19532078019472 2016 7.75660164983683 2017 7.02947039391439 2018 6.52130440486035 2019 4.94032133508388 2020 6.20570923789541 2021 5.82385034444983 2022 4.91605345189016