Year	Percent
1991	55.006
1992	55.506
1993	55.663
1994	53.434
1995	53.952
1996	54.203
1997	56.112
1998	55.965
1999	56.245
2000	56.445
2001	56.319
2002	56.568
2003	57.534
2004	57.923
2005	58.854
2006	58.251
2007	58.497
2008	59.456
2009	60.225
2010	60.211
2011	61.011
2012	61.086
2013	61.655
2014	61.012
2015	59.451
2016	61.428
2017	61.218
2018	61.42
2019	61.745
2020	61.938
2021	62.101
2022	62.213