Year	Percent
1991	10.075
1992	9.986
1993	9.596
1994	12.501
1995	13.257
1996	13.257
1997	12.458
1998	12.635
1999	12.927
2000	13.698
2001	14.02
2002	14.12
2003	13.838
2004	13.297
2005	13.501
2006	12.997
2007	12.926
2008	13.101
2009	13.46
2010	14.297
2011	14.954
2012	14.556
2013	13.557
2014	13.601
2015	14.165
2016	14.666
2017	14.49
2018	14.679
2019	14.796
2020	14.912
2021	14.996
2022	15.097