Year	Percent
1991	30.14
1992	29.359
1993	28.504
1994	24.146
1995	27.121
1996	26.349
1997	34.233
1998	37.719
1999	44.3
2000	52.955
2001	53.851
2002	55.419
2003	56.404
2004	55.24
2005	55.745
2006	56.806
2007	57.262
2008	57.646
2009	61.544
2010	62.735
2011	63.303
2012	63.173
2013	64.12
2014	66.389
2015	53.406
2016	62.076
2017	62.216
2018	62.833
2019	63.415
2020	63.972
2021	64.554
2022	65.101