Year	Percent
1991	23.616
1992	13.59
1993	14.249
1994	13.199
1995	16.009
1996	17.482
1997	17.907
1998	16.83
1999	17.312
2000	16.715
2001	15.93
2002	17.79
2003	17.92
2004	15.696
2005	14.833
2006	14.912
2007	11.705
2008	8.953
2009	9.375
2010	8.826
2011	8.782
2012	8.972
2013	9.689
2014	10.272
2015	10.055
2016	9.559
2017	9.693
2018	9.679
2019	9.663
2020	9.635
2021	9.616
2022	9.6