Year	Percent
1991	59.47
1992	59.926
1993	59.648
1994	59.674
1995	58.728
1996	58.42
1997	57.891
1998	57.93
1999	57.647
2000	57.463
2001	57.072
2002	56.601
2003	56.622
2004	56.056
2005	55.726
2006	55.441
2007	55.001
2008	54.675
2009	51.027
2010	51.808
2011	55.236
2012	64.297
2013	53.092
2014	54.247
2015	55.389
2016	58.237
2017	58.148
2018	58.036
2019	57.921
2020	57.804
2021	57.687
2022	57.573