Year % gross 1971 0.506850004196167 1972 0.556159973144531 1973 0.591109991073608 1974 0.616540014743805 1975 0.671199977397919 1976 0.652729988098145 1977 0.620459973812103 1978 0.599929988384247 1981 0.749279975891113 1984 0.63305002450943 1985 0.640240013599396 1986 1.70780003070831 1988 1.55036997795105 1989 1.42839002609253 1990 1.35529005527496 1991 1.20103001594543 2000 1.61407005786896 2001 2.03906989097595 2002 1.92174005508423