Year	Percent
1991	23.306
1992	9.14
1993	11.806
1994	13.583
1995	11.997
1996	12.627
1997	18.229
1998	16.102
1999	15.507
2000	13.554
2001	13.297
2002	11.357
2003	10.945
2004	12.731
2005	9.811
2006	9.963
2007	8.936
2008	7.528
2009	8.785
2010	9.435
2011	9.145
2012	9.028
2013	9.371
2014	8.824
2015	9.526
2016	9.916
2017	10.294
2018	10.29
2019	10.243
2020	10.204
2021	10.19
2022	10.173