Year	Percent
1990	70.328
1991	70.243
1992	69.959
1993	69.279
1994	67.771
1995	66.621
1996	65.868
1997	65.088
1998	64.382
1999	63.322
2000	63.558
2001	63.837
2002	62.944
2003	62.33
2004	62.243
2005	63.029
2006	62.372
2007	62.303
2008	63.094
2009	63.797
2010	64.264
2011	64.483
2012	64.73
2013	64.874
2014	65.231
2015	65.082
2016	65.432
2017	65.109
2018	64.758
2019	64.367
2020	63.93
2021	63.409
2022	62.846
2023	62.273
2024	61.74
2025	61.277
2026	60.851
2027	60.498
2028	60.199
2029	59.929
2030	59.667