Year	Percent
1991	59.651
1992	58.343
1993	57.397
1994	56.576
1995	53.356
1996	55.713
1997	57.641
1998	56.21
1999	54.56
2000	53.063
2001	54.459
2002	54.859
2003	55.794
2004	59.623
2005	62.045
2006	63.493
2007	62.075
2008	63.158
2009	63.751
2010	64.368
2011	63.34
2012	62.332
2013	64.381
2014	61.242
2015	60.7
2016	61.775
2017	61.73
2018	61.619
2019	61.444
2020	61.19
2021	60.816
2022	60.316