Year % 2001 18.83900358851354 2002 18.621171614663456 2003 16.892675388368602 2004 19.278415142900606 2005 18.66033920898332 2006 18.110987194923936 2007 19.503223375844566 2008 17.192778101339545 2009 20.665832657031395 2010 20.02003143930532 2011 17.023971488975512 2012 18.40068321391709 2013 19.970518142957452 2014 19.803128530655652 2015 18.60684681165294 2016 20.03914732721094 2017 22.470742811325657 2018 19.234283732139076 2019 18.744417360572392 2020 18.664986665697565 2021 16.767584506756457 2022 16.482445086765857 2023 14.617697175091923