Year	Percent
1991	14.453
1992	14.083
1993	14.073
1994	15.945
1995	17.837
1996	18.752
1997	19.982
1998	20.123
1999	18.915
2000	19.484
2001	18.422
2002	17.922
2003	19.071
2004	18.811
2005	16.688
2006	15.876
2007	15.084
2008	14.691
2009	14.841
2010	14.762
2011	14.547
2012	14.118
2013	14.919
2014	15.319
2015	14.895
2016	14.211
2017	14.175
2018	14.132
2019	14.099
2020	14.078
2021	14.057
2022	14.058