Year	Percent
1991	65.974
1992	66.537
1993	65.882
1994	65.872
1995	66.083
1996	65.755
1997	62.613
1998	61.512
1999	63.541
2000	64.312
2001	64.995
2002	60.907
2003	62.319
2004	62.147
2005	63.156
2006	64.96
2007	66.412
2008	67.133
2009	65.23
2010	61.538
2011	62.752
2012	62.717
2013	60.676
2014	60.446
2015	59.501
2016	60.922
2017	61.185
2018	61.659
2019	62.081
2020	62.192
2021	62.184
2022	62.149