Year	%
1970	64.11395
1971	80.08524
1972	86.91808
1973	84.73746
1975	88.98814
1976	85.77916
1980	71.40941
1981	97.12117
1982	95.066
1983	94.6642
1987	89.61896
1988	83.92977
1991	86.85471
1992	88.18522
1995	90.59665
2000	93.8878
2001	94.72951
2002	96.33978
2005	94.93641
2006	94.56336
2007	94.373
2008	96.10065
2009	97.16131
2010	95.94442
2011	95.23883
2012	93.63535
2013	93.29435
2014	93.12812
2015	92.38631
2016	91.72116
2017	95.08438