Year	Percent
1990	65.257
1991	65.251
1992	65.184
1993	65.204
1994	65.359
1995	65.483
1996	65.496
1997	65.53
1998	65.686
1999	65.738
2000	65.617
2001	65.316
2002	65.098
2003	64.676
2004	63.942
2005	64.357
2006	64.727
2007	65.155
2008	65.635
2009	65.124
2010	65.359
2011	65.356
2012	65.412
2013	65.488
2014	65.567
2015	65.41
2016	65.413
2017	65.375
2018	65.225
2019	64.953
2020	64.554
2021	63.997
2022	63.315
2023	62.553
2024	61.786
2025	61.066
2026	60.388
2027	59.77
2028	59.236
2029	58.812
2030	58.509