Year	% gross
1970	38.0917205810547
1971	38.0904197692871
1972	37.9575386047363
1973	40.5069198608398
1974	43.105640411377
1975	47.7337608337402
1976	52.0834312438965
1977	50.9880218505859
1978	48.6998596191406
1979	48.5291213989258
1980	48.8887100219727
1981	52.6760902404785
1982	52.866828918457
1983	54.6981811523438
1984	56.5861701965332
1985	57.3119010925293
1986	60.9816513061523
1987	61.8071517944336
1988	61.5293388366699
1989	60.4498291015625
1990	61.040168762207
1991	64.8055572509766
1992	65.9547882080078
1993	66.9706726074219
1994	68.097412109375
1995	69.2385330200195
1996	70.7012481689453
1997	68.1510925292969
1998	65.6810531616211
1999	63.0685081481934
2000	60.526969909668
2001	63.2007713317871
2002	65.8832321166992
2003	65.015266418457
2004	64.1515808105469
2005	69.4920272827148
2006	61.5068016052246
2007	60.5678787231445
2008	59.6234512329102
2009	59.304500579834
2010	61.9667587280273
2011	64.6272430419922
2012	67.2670135498047
2013	69.8711013793945
2014	63.6123008728027
2015	70.1195526123047
2016	69.9591293334961
2017	70.8075866699219
2018	70.0504531860352
2019	70.1460723876953
2020	70.3025817871094
