Year	% gross
1971	8.90297985076904
1972	9.73904991149902
1973	12.1512603759766
1979	38.8518600463867
1980	40.8125915527344
1984	35.8589706420898
1988	32.4345703125
2008	35.5695495605469
2012	34.1356582641602
2015	41.5908699035645
2018	45.0853614807129
2019	44.5243911743164
2020	51.7921714782715