Year % (cumulative) 2006 14.9976816177368 2007 15.2326955795288 2008 14.8938207626343 2009 15.1674585342407 2010 16.9575595855713 2012 16.7553310394287 2013 17.4730472564697 2014 18.7892284393311 2015 19.9553298950195 2016 20.3266925811768 2017 20.6887607574463 2018 21.8244743347168 2019 21.3153133392334 2020 21.2829914093018 2021 21.0686283111572 2022 20.6884708404541