Year	Percent
1991	64.53
1992	63.642
1993	63.655
1994	62.829
1995	63.261
1996	63.513
1997	63.234
1998	62.88
1999	62.627
2000	61.625
2001	61.408
2002	60.721
2003	59.507
2004	58.568
2005	57.366
2006	55.931
2007	53.879
2008	53.037
2009	52.216
2010	51.363
2011	52.703
2012	55.885
2013	55.893
2014	55.38
2015	54.86
2016	54.55
2017	55.541
2018	55.368
2019	55.208
2020	55.066
2021	54.884
2022	54.685