Year	Percent
1991	7.642
1992	7.85
1993	7.945
1994	8.024
1995	8.237
1996	8.446
1997	8.311
1998	7.898
1999	8.201
2000	8.21
2001	8.266
2002	8.382
2003	8.691
2004	8.929
2005	9.429
2006	10.067
2007	10.423
2008	10.458
2009	10.468
2010	10.709
2011	10.83
2012	11.282
2013	11.497
2014	11.793
2015	11.957
2016	12.006
2017	12.344
2018	12.558
2019	12.805
2020	13.07
2021	13.345
2022	13.638