Year	Percent
1991	52.504
1992	53.047
1993	53.622
1994	55.424
1995	55.166
1996	54.752
1997	57.298
1998	56.731
1999	56.129
2000	55.886
2001	56.027
2002	56.357
2003	57.522
2004	58.689
2005	58.727
2006	59.756
2007	57.835
2008	60.133
2009	60.214
2010	60.121
2011	60.005
2012	56.323
2013	57.077
2014	59.163
2015	52.438
2016	52.771
2017	52.88
2018	53.003
2019	53.122
2020	53.247
2021	53.396
2022	53.555