Year	% gross
1970	9.34745025634766
1971	10.1811504364014
1972	11.8570699691772
1975	16.2745494842529
1976	14.5088195800781
1978	20.8381595611572
1979	22.6867599487305
1980	22.5204906463623
1999	30.4185695648193
2000	35.034351348877
2011	44.5974807739258
2014	37.1417808532715
2015	36.6230812072754
2020	37.8051300048828