Year	Percent
1991	14.575
1992	14.352
1993	14.158
1994	13.989
1995	14.599
1996	15.241
1997	15.921
1998	16.629
1999	17.33
2000	14.852
2001	12.53
2002	10.45
2003	8.558
2004	6.86
2005	5.332
2006	5.573
2007	5.272
2008	4.981
2009	4.697
2010	2.752
2011	2.827
2012	3.265
2013	3.357
2014	3.283
2015	3.19
2016	3.163
2017	2.937
2018	2.722
2019	2.528
2020	2.336
2021	2.148
2022	1.973