Year	% gross
1970	12.113730430603
1971	12.1860799789429
1972	12.3646697998047
1973	12.5466899871826
1974	12.8781604766846
1975	13.64564037323
1976	14.1663398742676
1977	14.7531299591064
1978	15.4853897094727
1979	15.8876600265503
1980	16.8235893249512
1981	16.6147994995117
1982	16.8129997253418
1983	16.9655494689941
1984	17.3327503204346
1985	17.469539642334
1986	18.0125007629395
1987	18.2401008605957
1988	18.9048309326172
1989	18.8318099975586
1990	18.6261692047119
1991	18.6937808990479
1992	18.4707202911377
1993	18.1122398376465
1994	18.4015102386475
1995	18.6381206512451
1996	18.7325897216797
1997	15.5137596130371
1998	17.3875408172607
1999	18.6026802062988
2000	20.4294891357422
2001	21.7956600189209
2002	22.9902591705322
2003	24.9371795654297
2004	27.433910369873
2005	30.2026500701904
2006	34.034538269043
2007	36.0491905212402
2008	38.1538581848145
2009	40.2832717895508
2010	42.5288009643555
2011	45.7974586486816
2012	48.591251373291
2013	51.5309715270996
2014	50.4999809265137
2015	52.6934089660645
2016	54.5761413574219
2017	56.8278007507324
2018	57.4729614257813
2019	58.6672782897949
2020	58.4978103637695