Year	Percent
1991	12.681
1992	12.165
1993	12.084
1994	11.64
1995	11.918
1996	11.965
1997	11.778
1998	11.019
1999	10.207
2000	10.076
2001	10.127
2002	10.509
2003	10.5
2004	10.878
2005	11.095
2006	11.306
2007	11.634
2008	12.598
2009	13.099
2010	13.904
2011	14.302
2012	14.395
2013	14.052
2014	14.036
2015	14.547
2016	13.967
2017	14.093
2018	14.174
2019	14.191
2020	14.214
2021	14.136
2022	13.972