Year	Percent
1991	7.946
1992	9.855
1993	13.583
1994	18.29
1995	10.604
1996	10.388
1997	9.916
1998	9.724
1999	9.114
2000	8.089
2001	9.294
2002	6.622
2003	8.823
2004	7.767
2005	7.216
2006	8.811
2007	7.777
2008	9.999
2009	10.797
2010	9.989
2011	9.225
2012	10.431
2013	11.673
2014	12.536
2015	13.385
2016	13.684
2017	14.124
2018	14.454
2019	14.395
2020	14.508
2021	14.363
2022	14.485