Year	Percent
1991	26.394
1992	24.862
1993	22.755
1994	22.633
1995	21.044
1996	18.811
1997	17.502
1998	18.11
1999	17.522
2000	16.665
2001	17.105
2002	14.963
2003	14.35
2004	13.104
2005	12.586
2006	12.751
2007	12.886
2008	12.998
2009	11.702
2010	11.485
2011	10.367
2012	9.353
2013	7.946
2014	9.632
2015	9.621
2016	9.093
2017	9.073
2018	8.959
2019	8.824
2020	8.703
2021	8.607
2022	8.472