Year	Percent
1991	60.938
1992	61.476
1993	62.41
1994	62.639
1995	63.04
1996	62.217
1997	62.717
1998	63.331
1999	63.168
2000	63.173
2001	63.672
2002	63.608
2003	63.274
2004	62.364
2005	62.221
2006	61.81
2007	61.437
2008	60.795
2009	60.661
2010	60.224
2011	59.625
2012	59.145
2013	58.485
2014	57.808
2015	57.488
2016	57.338
2017	57.286
2018	57.236
2019	57.176
2020	57.106
2021	57.03
2022	56.95