Year	%
1984	96.8681
1985	97.55261
1991	97.56819
1993	96.88721
1994	96.2082
1995	97.11732
1996	97.30426
1997	97.2096
1998	97.72501
1999	97.90097
2000	98.06083
2001	98.00318
2002	97.99366
2003	97.94481
2004	97.93552
2005	97.74361
2006	97.48563
2007	97.63072
2008	97.62012
2009	97.46991
2010	97.49715
2011	97.50502
2012	97.43727
2013	97.53512
2014	97.59163
2015	97.63889
2016	97.64045
2017	97.704