Year	Percent
1991	52.838
1992	52.706
1993	52.645
1994	51.799
1995	53.312
1996	53.114
1997	52.702
1998	52.071
1999	54.961
2000	60.043
2001	59.251
2002	58.64
2003	58.551
2004	59.439
2005	59.295
2006	51.749
2007	50.09
2008	51.534
2009	51.684
2010	51.175
2011	51.526
2012	51.193
2013	50.918
2014	50.565
2015	50.249
2016	49.92
2017	49.811
2018	49.703
2019	49.593
2020	49.482
2021	49.37
2022	49.26