Year	Percent
1991	67.133
1992	67.781
1993	67.829
1994	67.35
1995	67.111
1996	64.407
1997	63.786
1998	63.771
1999	63.584
2000	65.647
2001	66.7
2002	63.27
2003	65.962
2004	63.126
2005	62.142
2006	62.123
2007	63.482
2008	61.762
2009	61.207
2010	61.628
2011	64.143
2012	65.844
2013	65.02
2014	67.328
2015	68.122
2016	67.486
2017	67.972
2018	68.17
2019	68.33
2020	68.376
2021	68.293
2022	68.119