Year Average 1990 = 100 1975-12-31 199.19 1976-12-31 155.29 1977-12-31 145.02 1978-12-31 136.21 1979-12-31 136.35 1980-12-31 127.57 1981-12-31 114.76 1982-12-31 112.82 1983-12-31 106.92 1984-12-31 104.65 1985-12-31 98.66 1986-12-31 104.1 1987-12-31 100.06 1988-12-31 97.63 1989-12-31 99.46 1990-12-31 99.5 1991-12-31 99.07 1992-12-31 83.91 1993-12-31 76.82 1994-12-31 73.81 1995-12-31 70.95 1996-12-31 77.94 1997-12-31 75.67 1998-12-31 76.36 1999-12-31 73.17 2000-12-31 72.8 2001-12-31 72.52