Year	% gross
1970	1.54477000236511
1971	1.58666002750397
1972	1.4765100479126
1973	1.5884200334549
1974	1.86032998561859
1975	1.93950998783112
1976	2.18955993652344
1977	2.25305008888245
1978	2.28248000144958
1979	2.39175009727478
1981	2.16489005088806
1982	2.1360399723053
1983	2.17855000495911
1985	2.54668998718262
1986	2.78583002090454
1987	3.06539011001587
1988	3.49660992622375
1989	3.79560995101929
1991	4.4880199432373
1992	4.54813003540039
1993	4.55417013168335
1994	4.59988021850586
1995	4.66393995285034
1996	4.70808982849121
1997	4.89850997924805
2010	28.4753303527832
2014	29.5736999511719
2015	26.3641796112061
2016	26.1290798187256
2017	27.024169921875
2018	29.4335899353027
2019	31.2341194152832
2020	31.9762306213379
2021	28.9248294830322