Year	Percent
1991	12.24
1992	12.864
1993	13.122
1994	12.608
1995	11.453
1996	10.927
1997	11.41
1998	10.38
1999	9.606
2000	8.91
2001	8.213
2002	7.951
2003	7.875
2004	6.979
2005	6.436
2006	5.95
2007	5.749
2008	5.351
2009	4.807
2010	4.416
2011	4.395
2012	4.487
2013	4.635
2014	4.946
2015	4.668
2016	4.088
2017	4.123
2018	4.06
2019	3.988
2020	3.932
2021	3.872
2022	3.815