Year	Percent
1991	6.537
1992	6.293
1993	6.773
1994	7.219
1995	7.697
1996	7.881
1997	7.916
1998	7.487
1999	12.364
2000	11.732
2001	9.331
2002	8.952
2003	8.25
2004	7.893
2005	8.02
2006	7.77
2007	6.949
2008	6.739
2009	6.404
2010	5.57
2011	5.689
2012	5.414
2013	5.407
2014	5.16
2015	5.119
2016	5.026
2017	5.008
2018	4.928
2019	4.853
2020	4.783
2021	4.713
2022	4.639