Year	Percent
1991	5.532
1992	5.871
1993	5.707
1994	5.859
1995	5.964
1996	6.142
1997	6.138
1998	6.043
1999	6.115
2000	6.015
2001	6.384
2002	6.571
2003	6.4
2004	6.388
2005	6.186
2006	6.159
2007	7.994
2008	9.286
2009	9.943
2010	10.89
2011	12.798
2012	12.6
2013	12.41
2014	12.077
2015	11.83
2016	11.788
2017	11.77
2018	11.745
2019	11.707
2020	11.695
2021	11.695
2022	11.737