Year	%
2000	23.047105748631402
2001	22.662368399156133
2002	22.59150613366315
2003	22.519681458026252
2004	22.30880212459713
2005	21.779948177776802
2006	20.991517254181712
2007	20.47251555978855
2008	20.16756720571224
2009	19.854409722922988
2010	19.56109193804356
2011	19.21588749929884
2012	18.852321495446805
2013	18.381741092935695
2014	18.06110244446044
2015	17.79883021484292
2016	17.66523365230409
2017	17.35971254396641
2018	17.10316136376894
2019	16.949929816530343