Year % gross 2010 25.3540000915527 2011 23.1359996795654 2012 23.9160003662109 2013 23.0841999053955 2014 23.673999786377 2015 19.0030002593994 2016 18.3209991455078 2017 16.5100002288818 2018 15.875 2019 15.2810001373291 2020 14.878999710083 2021 15.7449998855591 2022 15.9010000228882