Year	Percent
1991	5.981
1992	6.119
1993	6.256
1994	6.11
1995	6.853
1996	6.213
1997	6.498
1998	6.596
1999	6.663
2000	6.615
2001	7.009
2002	7.05
2003	6.428
2004	7.065
2005	6.812
2006	7.284
2007	7.437
2008	7.783
2009	8.218
2010	7.929
2011	9.212
2012	7.687
2013	7.357
2014	7.063
2015	7.032
2016	6.726
2017	6.212
2018	6.684
2019	6.978
2020	6.782
2021	6.669
2022	6.583