Year	%
1984	96.7075
1985	97.277
1991	97.40873
1993	97.10737
1994	96.44872
1995	96.79618
1996	97.16634
1997	96.87169
1998	97.13145
1999	97.17217
2000	97.98695
2001	98.00751
2002	97.98294
2003	97.92362
2004	97.94501
2005	97.88364
2006	97.78132
2007	97.7646
2008	97.83817
2009	97.71729
2010	97.71879
2011	97.6348
2012	97.66925
2013	97.78411
2014	97.77966
2015	97.69559
2016	97.84529
2017	97.92222