Year	Percent
1991	74.78
1992	62.811
1993	65.311
1994	70.272
1995	66.805
1996	71.168
1997	71.878
1998	71.087
1999	72.036
2000	68.761
2001	68.03
2002	68.074
2003	67.235
2004	65.83
2005	70.057
2006	70.138
2007	65.737
2008	64.726
2009	64.244
2010	64.693
2011	65.328
2012	62.594
2013	62.468
2014	62.758
2015	63.326
2016	63.968
2017	65.293
2018	66.246
2019	66.922
2020	66.757
2021	66.879
2022	66.915