Year	%
2000	20.595542733296593
2001	20.68675765685193
2002	20.586353151214432
2003	20.382964801024862
2004	20.111449176948447
2005	19.847242094764358
2006	19.63034236990338
2007	19.334175292496337
2008	19.203812144029836
2009	19.107442197003923
2010	18.91321504010307
2011	18.530622503617384
2012	18.693033513130075
2013	18.306187886229157
2014	18.321073360072834
2015	18.556981078022368
2016	18.212043137227294
2017	17.825511526014477
2018	17.855160184972313
2019	17.761691833493874