Year	Percent
1972	76.43112
1973	82.93987
1974	96.01914
1975	104.88825
1976	104.37409
1977	103.33918
1978	102.98117
1979	102.02832
1980	101.29967
1981	97.33869
1982	94.64853
1983	89.47051
1984	91.78633
1985	91.79084
1987	83.62737
1988	86.98182
1989	88.95971
1990	91.54559
1991	93.37301
1992	93.88916
1993	91.89732
1994	95.48503
1996	90.80679
1999	91.30056
2000	93.22347
2002	91.17966
2003	93.98301
2004	95.00773