Year	% gross
1971	14.4087696075439
1972	15.7502603530884
1973	17.4486808776855
1974	18.2363700866699
1975	19.0955791473389
1976	19.453929901123
1977	19.8587093353271
1978	22.1396503448486
1979	18.3291301727295
1980	17.1338691711426
1981	16.2023506164551
1982	15.7331304550171
1983	15.445969581604
1984	16.1458892822266
1985	17.3745307922363
1986	19.1692790985107
1987	20.9221801757812
1988	22.4143390655518
1989	24.5839595794678
1990	25.5723209381104
1991	30.4806594848633
1992	30.3537998199463
1993	31.8155403137207
1994	33.443531036377
1995	35.8240814208984
1996	39.6896896362305
1997	41.8087997436523
1998	42.1581192016602
1999	44.0834083557129
2000	42.3398284912109
2001	41.0407791137695
2002	41.4290084838867
2003	42.8536109924316
2004	43.6935691833496
2005	46.225269317627
2006	47.7948303222656
2007	51.2403411865234
2008	52.6504096984863
2009	55.0083694458008
2010	58.354850769043
2011	59.8246803283691
2012	62.1616516113281
2013	65.3930816650391
2014	69.5866012573242
2015	74.0448913574219
2016	75.474853515625
2017	76.0799179077148
2018	76.2302093505859
2019	75.3370971679688
2020	74.3762283325195
2021	74.0276489257812