Year	Percent
1991	24.624
1992	22.039
1993	21.364
1994	19.32
1995	18.474
1996	17.861
1997	16.551
1998	16.668
1999	15.625
2000	16.489
2001	15.99
2002	15.904
2003	15.72
2004	15.714
2005	16.088
2006	14.857
2007	13.195
2008	12.899
2009	14.055
2010	13.016
2011	12.084
2012	11.024
2013	11.518
2014	12.454
2015	11.657
2016	10.466
2017	10.435
2018	10.277
2019	10.175
2020	10.085
2021	10.008
2022	9.943