Year	Percent
1991	6.579
1992	6.052
1993	6.273
1994	6.546
1995	6.906
1996	7.269
1997	7.306
1998	7.704
1999	8.441
2000	8.767
2001	9.115
2002	9.517
2003	9.669
2004	10.09
2005	10.56
2006	10.714
2007	11.116
2008	11.356
2009	11.545
2010	12.492
2011	12.615
2012	12.508
2013	13.637
2014	13.926
2015	14.267
2016	14.475
2017	14.638
2018	15.021
2019	15.329
2020	15.691
2021	16.019
2022	16.44