Year	Percent
1991	9.58
1992	9.28
1993	9.378
1994	9.291
1995	10.101
1996	9.613
1997	10.318
1998	10.463
1999	10.215
2000	8.877
2001	9.508
2002	9.144
2003	8.534
2004	9.053
2005	8.82
2006	8.69
2007	8.643
2008	8.634
2009	8.903
2010	8.049
2011	7.649
2012	7.687
2013	7.174
2014	7.318
2015	7.568
2016	7.618
2017	7.071
2018	6.972
2019	7.034
2020	6.902
2021	6.973
2022	6.989