Year	Percent
1991	65.496
1992	68.217
1993	67.958
1994	69.96
1995	65.773
1996	65.128
1997	65.172
1998	64.754
1999	64.988
2000	64.968
2001	64.579
2002	63.963
2003	63.67
2004	63.588
2005	62.908
2006	62.113
2007	61.317
2008	60.089
2009	59.652
2010	60.122
2011	59.266
2012	58.072
2013	57.14
2014	56.005
2015	55.231
2016	54.142
2017	53.997
2018	53.248
2019	52.541
2020	51.854
2021	51.159
2022	50.458