Year	Percent
1991	24.292
1992	24.352
1993	24.625
1994	23.857
1995	23.406
1996	21.964
1997	22.165
1998	22.848
1999	23.485
2000	12.961
2001	13.234
2002	13.08
2003	13.942
2004	13.955
2005	13.887
2006	13.224
2007	12.683
2008	12.93
2009	10.24
2010	10.264
2011	12.953
2012	11.419
2013	13.814
2014	20.726
2015	20.593
2016	20.666
2017	20.616
2018	20.404
2019	20.339
2020	20.305
2021	20.271
2022	20.258