Year	Percent
1991	59.503
1992	57.739
1993	56.724
1994	58.449
1995	57.502
1996	57.658
1997	57.507
1998	57.583
1999	56.303
2000	56.218
2001	56.5
2002	56.033
2003	55.396
2004	55.541
2005	56.294
2006	57.699
2007	58.059
2008	58.85
2009	58.395
2010	56.98
2011	55.703
2012	55.414
2013	56.859
2014	57.08
2015	56.201
2016	55.296
2017	56.505
2018	56.475
2019	56.445
2020	56.418
2021	56.389
2022	56.357