Year	Percent
1991	11.026
1992	11.578
1993	11.612
1994	11.247
1995	10.02
1996	9.905
1997	9.977
1998	9.344
1999	8.18
2000	8.264
2001	7.696
2002	7.186
2003	6.99
2004	6.843
2005	6.588
2006	6.394
2007	6.343
2008	6.202
2009	6.326
2010	6.006
2011	5.93
2012	5.888
2013	5.897
2014	6.09
2015	6.138
2016	5.516
2017	5.545
2018	5.458
2019	5.385
2020	5.315
2021	5.253
2022	5.191