Year	% gross
1971	40.3686790466309
1972	40.4956703186035
1973	43.2345504760742
1974	46.5352897644043
1975	53.558650970459
1976	56.2943801879883
1977	55.9465103149414
1978	53.5248908996582
1980	52.8050994873047
1981	55.9216194152832
1982	54.9106292724609
1983	55.7863616943359
1984	55.8426513671875
1985	56.8359107971191
1986	57.8579216003418
1987	58.4052085876465
1988	59.0596008300781
1989	59.8507995605469
1990	61.8734397888184
1991	61.1007118225098
1992	62.5083694458008
1993	61.7018203735352
1994	62.6347503662109
1995	63.7555694580078
1996	64.2955780029297
2018	48.2933387756348
2020	48.561939239502