Year	%
1989	92.19012
1990	83.00277
1991	37.90065
1992	35.02488
1993	26.8895
1994	26.21312
1995	23.908
1996	28.03999
1997	25.56112
1998	27.24773
1999	24.68571
2000	30.07378
2001	28.3348
2002	27.41852
2003	24.89694
2004	21.24102
2005	15.29219
2006	14.9761
2007	20.16921
2008	20.36638
2009	18.61734
2010	16.34924
2011	16.94217
2012	14.01938
2013	18.33313
2014	17.17599
2015	17.54996
2016	18.06025
2017	18.06553