Year	Percent
1990	66.36
1991	66.407
1992	66.418
1993	66.141
1994	66.456
1995	65.904
1996	65.55
1997	65.862
1998	65.688
1999	65.177
2000	65.203
2001	65.136
2002	65.141
2003	64.768
2004	64.396
2005	63.8
2006	62.621
2007	62.461
2008	62.41
2009	62.506
2010	62.191
2011	61.895
2012	61.515
2013	61.106
2014	60.813
2015	60.772
2016	60.752
2017	60.542
2018	60.331
2019	60.121
2020	59.91
2021	59.7
2022	59.49
2023	59.279
2024	59.069
2025	58.858
2026	58.648
2027	58.438
2028	58.227
2029	58.017
2030	57.806