Year	% gross
1971	99.4517135620117
1972	99.9489593505859
1973	101.807838439941
1974	105.780197143555
1975	109.624473571777
1976	113.379417419434
1977	112.344520568848
1978	108.829849243164
1979	106.466079711914
1980	105.692237854004
1981	106.783889770508
1982	108.01473236084
1983	111.410842895508
1984	114.080017089844
1985	117.143020629883
1986	106.265312194824
1987	103.062133789063
1988	97.7529983520508
1989	96.657341003418
1990	97.1255264282227
1991	99.1412200927734
1992	99.4373474121094
1993	98.1610412597656
1994	97.9605331420898
1995	99.7913513183594
1996	100.895431518555
1997	99.916389465332
2011	89.8003005981445
2012	90.4678497314453
2013	92.8246536254883
2014	93.5659713745117
2015	94.3068771362305
2016	95.1075210571289
2017	94.2880020141602
2018	88.9953994750977
2019	89.6316833496094
2020	91.9532470703125