Year	Percent
1991	6.515
1992	6.5
1993	6.433
1994	6.216
1995	6.139
1996	6.494
1997	6.706
1998	6.809
1999	6.854
2000	6.917
2001	7.1
2002	6.769
2003	7.355
2004	5.825
2005	5.121
2006	5.398
2007	5.589
2008	5.998
2009	6.086
2010	6.019
2011	6.407
2012	7.739
2013	7.999
2014	8.251
2015	8.588
2016	8.683
2017	8.737
2018	8.824
2019	8.901
2020	8.98
2021	9.055
2022	9.133