Year	Percent
1991	33.317
1992	33.166
1993	33.024
1994	32.818
1995	44.1
1996	44.445
1997	44.099
1998	43.76
1999	43.376
2000	32.185
2001	19.353
2002	17.965
2003	17.205
2004	19.696
2005	20.621
2006	20.116
2007	19.337
2008	17.646
2009	16.451
2010	16.007
2011	20.824
2012	19.789
2013	19.427
2014	19.949
2015	19.43
2016	18.256
2017	17.765
2018	17.72
2019	17.671
2020	17.624
2021	17.578
2022	17.533