Year	Percent
1991	64.774
1992	64.487
1993	63.152
1994	63.058
1995	63.97
1996	62.906
1997	63.241
1998	62.818
1999	61.873
2000	61.215
2001	57.884
2002	57.107
2003	57.13
2004	60.39
2005	60.307
2006	60.298
2007	59.736
2008	57.908
2009	56.863
2010	57.605
2011	59.684
2012	63.809
2013	60.328
2014	56.734
2015	54.94
2016	55.267
2017	60.373
2018	62.698
2019	63.841
2020	65.118
2021	65.798
2022	66.163