Year	Percent
1991	13.645
1992	13.053
1993	12.504
1994	11.275
1995	10.867
1996	10.284
1997	11.22
1998	12.736
1999	14.428
2000	17.12
2001	6.013
2002	7.701
2003	12.142
2004	15.494
2005	19.409
2006	23.743
2007	21.522
2008	19.739
2009	19.948
2010	21.007
2011	22.737
2012	22.811
2013	21.654
2014	21.198
2015	21.7
2016	20.796
2017	20.912
2018	20.463
2019	19.89
2020	19.37
2021	18.838
2022	18.307