Year	Percent
2000	80.24178
2001	80.23735
2002	80.23256
2003	80.22742
2004	80.22193
2005	80.21608
2006	80.20989
2007	80.20333
2008	80.19643
2009	80.18917
2010	80.18155
2011	80.17359
2012	80.16527
2013	80.15659
2014	80.14756
2015	80.13818
2016	80.12845
2017	80.11836
2018	80.10792
2019	80.09712
2020	80.08597
2021	80.19943
2022	80.31289