Year	Percent
1991	32.861
1992	32.061
1993	30.324
1994	28.432
1995	25.048
1996	25.981
1997	26.649
1998	25.295
1999	24.861
2000	21.001
2001	20.817
2002	20.484
2003	20.257
2004	19.306
2005	16.804
2006	16.819
2007	17.49
2008	16.717
2009	22.547
2010	21.472
2011	14.079
2012	14.104
2013	14.118
2014	11.913
2015	11.82
2016	11.694
2017	11.719
2018	11.599
2019	11.456
2020	11.32
2021	11.174
2022	11.02