Year	Percent
1991	20.793
1992	21.806
1993	22.961
1994	20.642
1995	19.536
1996	17.036
1997	14.766
1998	12.89
1999	13.548
2000	12.738
2001	10.908
2002	10.435
2003	12.835
2004	10.493
2005	8.879
2006	7.34
2007	6.098
2008	6.261
2009	5.302
2010	5.151
2011	1.712
2012	1.646
2013	1.608
2014	1.681
2015	1.615
2016	1.631
2017	1.608
2018	1.637
2019	1.633
2020	1.632
2021	1.525
2022	1.396