Year	Percent
1991	57.936
1992	57.656
1993	58.481
1994	59.275
1995	59.653
1996	60.673
1997	62.221
1998	62.137
1999	61.078
2000	60.568
2001	61.157
2002	62.226
2003	62.177
2004	61.472
2005	61.292
2006	60.737
2007	59.643
2008	58.131
2009	55.993
2010	54.735
2011	57.5
2012	58.258
2013	56.457
2014	57.354
2015	58.681
2016	59.579
2017	59.797
2018	60.08
2019	60.335
2020	60.613
2021	60.875
2022	61.114