Year	Percent
1991	14.819
1992	13.494
1993	10.564
1994	12.517
1995	12.611
1996	10.801
1997	15.46
1998	13.976
1999	12.616
2000	12.991
2001	11.757
2002	12.205
2003	12.406
2004	12.61
2005	11.113
2006	10.08
2007	9.423
2008	9.842
2009	9.845
2010	10.117
2011	9.43
2012	8.835
2013	9.093
2014	9.357
2015	8.845
2016	8.956
2017	9
2018	8.963
2019	8.935
2020	8.913
2021	8.892
2022	8.885