Year	Percent
1971	95.41615
1972	90.17654
1973	91.63156
1974	92.6746
1976	87.88268
1977	93.53092
1978	86.76957
1979	90.27926
1980	80.61295
1982	84.34675
1987	85.87767
1992	89.89476
1993	87.38128
1995	77.49472
1996	77.88106
1997	84.88579
1999	102.34424
2000	101.61533
2001	93.523
2003	77.15914
2005	90.08115
2006	92.36414
2007	91.69228
2008	95.61006
2009	99.43917
2010	94.76064
2011	99.5961
2012	97.98084