Year	Percent
1991	74.725
1992	74.837
1993	74.649
1994	74.606
1995	74.157
1996	73.474
1997	72.35
1998	70.246
1999	67.404
2000	63.824
2001	59.437
2002	66.475
2003	67.484
2004	67.964
2005	67.959
2006	67.232
2007	66.116
2008	63.382
2009	63.696
2010	64.191
2011	64.454
2012	63.183
2013	62.262
2014	61.161
2015	60.45
2016	60.23
2017	59.715
2018	59.183
2019	58.194
2020	57.858
2021	57.534
2022	57.217