Year	Percent
1991	5.457
1992	5.301
1993	5.216
1994	5.204
1995	5.593
1996	5.646
1997	5.641
1998	5.956
1999	5.947
2000	6.254
2001	6.422
2002	6.713
2003	6.439
2004	6.622
2005	6.193
2006	6.139
2007	6.366
2008	6.375
2009	6.632
2010	6.334
2011	6.411
2012	6.601
2013	6.35
2014	6.518
2015	6.633
2016	6.539
2017	7.178
2018	7.164
2019	7.191
2020	7.16
2021	7.123
2022	7.083