Year	% gross
1976	21.7950096130371
1977	21.8721294403076
1978	21.9245090484619
1979	22.3445301055908
1980	22.3844108581543
1981	22.4301300048828
1982	22.3781204223633
1983	22.692850112915
1984	22.9296092987061
1985	23.0461597442627
1986	23.2887001037598
1987	23.1881408691406
1988	23.4978809356689
1989	23.7012901306152
1990	23.8306007385254
1991	25.2750301361084
1992	25.0850505828857
1993	26.0258693695068
1994	25.6172790527344
1995	25.770959854126
1996	26.2526206970215
1997	26.910400390625
1998	26.5774707794189
1999	26.6835403442383
2000	26.5150203704834
2001	27.9237995147705
2002	28.897819519043
2003	29.1726398468018
2004	29.9115200042725
2005	30.455020904541
2006	30.767599105835
2007	31.7001895904541
2008	33.702320098877
2009	34.7073707580566
2010	34.9137496948242
2011	36.197868347168
2012	35.8943710327148
2013	36.2019805908203
2014	37.489330291748
2015	38.2789306640625
2016	38.5232696533203
2017	38.6277885437012
2018	39.2419509887695
2019	39.4355888366699
2020	39.6299514770508