Year	Percent
1991	52.436
1992	52.509
1993	52.856
1994	54.092
1995	54.512
1996	54.931
1997	55.674
1998	56.038
1999	56.361
2000	56.604
2001	56.074
2002	55.306
2003	55.146
2004	55.014
2005	55.274
2006	55.642
2007	55.64
2008	55.294
2009	53.461
2010	52.55
2011	52.113
2012	52.225
2013	52.308
2014	52.708
2015	52.941
2016	53.308
2017	53.332
2018	53.262
2019	53.002
2020	52.807
2021	52.575
2022	52.338