Year	% gross
1971	12.4215402603149
1972	17.5558300018311
1973	17.5840091705322
1974	15.8222703933716
1975	17.7646808624268
1976	19.6362705230713
1977	26.4005603790283
1978	22.0922393798828
1979	23.8248596191406
1980	23.7840995788574
1981	24.0444793701172
1982	30.2259902954102
1983	26.7879199981689
1984	27.8295192718506
1985	24.2844200134277
1986	20.17746925354
1987	17.9678192138672
1988	18.6760292053223
1989	19.3076305389404
1990	20.1039295196533
1991	16.5348091125488
1992	18.695650100708
1993	20.527379989624
1994	23.3956604003906
1995	23.3740901947021
1996	25.4759292602539
1997	26.1194000244141
1998	28.4079093933105
1999	26.3228397369385
2000	29.0745296478271
2001	29.3906002044678
2002	33.630859375
2003	39.8489418029785
2004	38.6941795349121
2005	41.717041015625
2006	40.3929405212402
2007	44.7114906311035
2008	53.4309196472168
2009	56.4434509277344
2011	54.8820114135742
2013	51.0813217163086
2014	53.913501739502
2015	56.6042213439941
2016	58.2156410217285
2017	59.1914291381836
2018	59.9133415222168
2019	61.027400970459
2020	62.3124885559082
2021	53.8317413330078
