Year	%
2000	23.753022207842648
2001	23.748480333517314
2002	23.555624376384547
2003	23.45774798786724
2004	23.310882139857213
2005	23.06287415340708
2006	22.924619506476567
2007	22.790496654788495
2008	22.514144238818535
2009	22.32737695374248
2010	22.124892463730735
2011	21.980041820262947
2012	21.83119213625418
2013	21.62204604915872
2014	21.331945837705177
2015	21.04068467489104
2016	20.79704157408079
2017	20.472531206990038
2018	20.240927513954492
2019	20.010833662183327