Year	% gross
1970	14.5687799453735
1971	15.9250602722168
1972	18.504280090332
1975	24.6296405792236
1976	22.0609302520752
1978	29.6698703765869
1979	32.5753211975098
1980	32.0985794067383
1999	37.2386093139648
2000	40.9658508300781
2011	49.5684509277344
2014	42.1390113830566
2015	41.6106796264648
2020	38.5135803222656