Year	Percent
1991	10.908
1992	10.111
1993	10.516
1994	11.361
1995	10.428
1996	7.907
1997	8.075
1998	7.011
1999	8.544
2000	7.415
2001	5.917
2002	5.475
2003	7.157
2004	6.783
2005	7.068
2006	6.489
2007	6.067
2008	6.43
2009	6.87
2010	6.798
2011	7.284
2012	8.104
2013	8.051
2014	7.351
2015	8.754
2016	8.754
2017	8.825
2018	8.679
2019	8.547
2020	8.447
2021	8.36
2022	8.286
