Year	Percent
1990	65.368
1991	65.31
1992	65.12
1993	64.801
1994	64.462
1995	64.126
1996	63.868
1997	63.621
1998	63.352
1999	63.161
2000	62.857
2001	62.868
2002	62.887
2003	62.708
2004	61.898
2005	61.712
2006	61.518
2007	61.318
2008	61.111
2009	60.894
2010	60.667
2011	60.424
2012	60.173
2013	59.908
2014	59.825
2015	59.786
2016	59.918
2017	59.804
2018	59.677
2019	59.543
2020	59.405
2021	59.258
2022	59.111
2023	58.968
2024	58.828
2025	58.695
2026	58.558
2027	58.432
2028	58.321
2029	58.23
2030	58.164