Year	Percent
1991	72.062
1992	69.902
1993	67.713
1994	66.84
1995	64.207
1996	63.111
1997	62.561
1998	62.359
1999	59.098
2000	56.629
2001	56.851
2002	56.624
2003	58.53
2004	58.067
2005	58.819
2006	63.348
2007	64.767
2008	65.07
2009	56.82
2010	54.152
2011	59.029
2012	60.838
2013	62.112
2014	63.489
2015	65.177
2016	65.335
2017	65.906
2018	65.67
2019	65.348
2020	64.975
2021	64.502
2022	63.987