Year 2010 = 100 1974 2.96856669530549 1975 3.38268174928329 1976 3.94794632417857 1977 4.27152009396934 1978 4.98644990641961 1979 5.52054453101666 1980 5.92600126548133 1981 6.4929975042921 1982 7.59013027876294 1983 8.7174434813052 1984 10.7271631340221 1985 13.5289953332746 1986 17.3861529927304 1987 22.8817120874147 1988 38.1555835730988 1989 68.7324216855785 1990 100 1991 148.002672442591 1992 228.877466352008 1993 318.347180465307 1994 376.396297373894