Year	Percent
1991	11.198
1992	10.584
1993	10.094
1994	10.188
1995	10.213
1996	9.804
1997	9.252
1998	9.155
1999	8.871
2000	8.439
2001	8.34
2002	8.26
2003	7.821
2004	7.602
2005	7.222
2006	6.863
2007	6.814
2008	7.147
2009	7.543
2010	7.345
2011	7.223
2012	7.031
2013	6.813
2014	6.746
2015	6.482
2016	6.476
2017	6.611
2018	6.474
2019	6.418
2020	6.379
2021	6.333
2022	6.29