Year	%
2000	19.41622202648551
2001	19.159195698550004
2002	19.20970721736764
2003	19.02664714980166
2004	18.554905965173003
2005	18.1363202107894
2006	17.69179071771977
2007	17.331416656621595
2008	17.0210271781082
2009	16.640331545369513
2010	16.502351145215133
2011	16.281072937757727
2012	16.02843779968271
2013	15.621912966092873
2014	15.459266995043546
2015	15.505911801832628
2016	15.394322782218547
2017	15.121878865376319
2018	14.974252900966743
2019	14.837550940812319