Year	Percent
1991	14.366
1992	15.435
1993	14.284
1994	13.297
1995	14.027
1996	14.328
1997	12.315
1998	11.922
1999	12.826
2000	11.769
2001	11.569
2002	10.862
2003	10.262
2004	9.327
2005	9.589
2006	9.329
2007	8.894
2008	6.653
2009	7.304
2010	8.606
2011	8.726
2012	8.653
2013	6.267
2014	6.831
2015	6.494
2016	5.419
2017	4.99
2018	4.447
2019	4.211
2020	3.998
2021	3.735
2022	3.519