Year	Percent
1971	96.11566
1972	96.30775
1973	91.51663
1974	91.03386
1976	88.43524
1977	92.95761
1978	88.17042
1979	84.43491
1980	78.37886
1982	84.92717
1987	90.02911
1992	92.67304
1993	92.32595
1995	75.86518
1996	82.52217
1997	84.25496
1999	98.46058
2000	104.10083
2001	81.63365
2003	71.87075
2005	92.8907
2006	92.65146
2007	94.97868
2008	95.45156
2009	99.55061
2010	94.10614
2011	98.71855
2012	97.34726