Year	Percent
1991	11.201
1992	10.496
1993	10.637
1994	10.535
1995	9.949
1996	9.535
1997	9.227
1998	8.966
1999	8.391
2000	7.789
2001	7.751
2002	7.234
2003	6.831
2004	6.661
2005	6.489
2006	5.855
2007	5.619
2008	5.126
2009	5.425
2010	5.584
2011	5.481
2012	5.709
2013	6.01
2014	5.902
2015	5.787
2016	5.947
2017	5.853
2018	5.745
2019	5.64
2020	5.531
2021	5.441
2022	5.363