Year	Percent
1971	103.63958
1972	99.80511
1973	97.84828
1974	97.53632
1975	97.64854
1976	97.9311
1977	101.89099
1978	97.5641
1979	89.06886
1980	103.7553
1981	102.17253
1982	97.90072
1983	97.36952
1984	98.0001
1985	98.37646
1986	100.39088
1987	101.70628
1988	99.80609
1989	99.85112
1990	102.2159
1991	102.03858
1992	99.81129
1994	97.24095
1998	99.95287
1999	99.13509
2000	98.52601
2001	98.89411
2002	96.30202
2003	96.361
2004	98.63617
2005	99.18274
2006	99.22719
2007	102.79446
2009	100.72637
2010	100.29541
2011	101.95702
2012	101.65658