Year	%
2000	20.18388726059552
2001	19.91720897052226
2002	19.931451310769646
2003	19.75824862236695
2004	19.35922128949245
2005	18.994036699825823
2006	18.648484508982165
2007	18.34790179126603
2008	18.05257570111549
2009	17.720060667865045
2010	17.589665943621952
2011	17.399979500817974
2012	17.17372651252429
2013	16.834614284653963
2014	16.62514875344185
2015	16.68238228662142
2016	16.560800680337337
2017	16.333047039917354
2018	16.200786858795052
2019	16.09998829259619