Year	Percent
1991	11.317
1992	11.444
1993	11.311
1994	11.793
1995	12.411
1996	11.971
1997	11.811
1998	11.316
1999	11.347
2000	11.781
2001	11.374
2002	12.068
2003	12.335
2004	13.477
2005	13.827
2006	14.627
2007	15.138
2008	15.121
2009	15.454
2010	15.677
2011	17.605
2012	18.96
2013	18.192
2014	18.14
2015	18.005
2016	17.7
2017	17.699
2018	17.671
2019	17.684
2020	17.708
2021	17.721
2022	17.647