Year	Percent
1991	10.654
1992	11.104
1993	11.05
1994	11.069
1995	10.221
1996	9.837
1997	11.899
1998	7.931
1999	8.602
2000	6.734
2001	5.888
2002	6.037
2003	5.106
2004	5.411
2005	4.654
2006	4.513
2007	4.159
2008	3.87
2009	3.456
2010	3.829
2011	3.525
2012	4.041
2013	3.616
2014	3.598
2015	3.513
2016	3.412
2017	3.598
2018	3.554
2019	3.532
2020	3.514
2021	3.493
2022	3.452