Year % 2010 15.6106698385287 2011 16.030572886153 2012 14.2124706293436 2013 13.1963039063774 2014 11.6632140397999 2015 12.2120311951283 2016 13.9922401618409 2017 13.9016753127001 2018 13.3153828499605 2019 14.2930860329848 2020 13.8107747217725 2021 12.3503346516383 2022 11.2973510723104