Year	% gross
1970	7.37385988235474
1971	7.31015014648438
1972	7.27107000350952
1973	7.25142002105713
1974	7.33570003509521
1975	8.30041980743408
1976	9.87240982055664
1977	10.7211303710938
1978	10.929220199585
1979	11.5457201004028
1980	11.6232500076294
1981	11.5201501846313
1982	11.735969543457
1983	11.6475496292114
1984	12.1188898086548
1985	11.3217601776123
1986	11.3758401870728
1987	11.5727195739746
1988	11.4886703491211
1989	12.0415201187134
1990	12.2115898132324
1991	12.5258102416992
1992	12.7112302780151
1993	12.1667098999023
1994	12.0914297103882
1995	12.3749103546143
1996	12.9246397018433
1997	13.4963397979736
1998	14.5125398635864
1999	14.012149810791
2000	14.8430099487305
2001	15.1452198028564
2002	15.8043699264526
2003	16.4796905517578
2004	17.3155097961426
2005	18.6252002716064
2006	21.1915607452393
2007	21.1630401611328
2008	22.4703903198242
2009	24.3449897766113
2010	25.4159393310547
2011	24.7114105224609
2012	24.489559173584
2013	24.289400100708
2014	27.1320705413818
2015	27.9237194061279
2016	27.9146404266357
2017	28.7989292144775
2018	29.2133693695068
2019	30.4510803222656
2020	30.9111404418945