Year	% gross
1970	15.423999786377
1971	15.1673002243042
1972	14.9511003494263
1973	14.9597997665405
1974	15.2070999145508
1975	15.7742795944214
1976	17.4920902252197
1977	20.4399700164795
1978	19.3249607086182
1979	19.5781097412109
1980	20.5995101928711
1981	21.998929977417
1982	22.3953609466553
1983	23.3632507324219
1984	24.2938499450684
1985	25.199649810791
1986	26.5908794403076
1987	27.7830200195313
1988	28.2412605285645
1989	28.1229496002197
1990	28.0328006744385
1991	28.176290512085
1992	28.3360805511475
1993	28.416690826416
1994	28.3016605377197
1995	28.7695598602295
1996	29.3819808959961
1997	27.8335304260254
1998	30.9506607055664
1999	31.622350692749
2000	32.5202713012695
2001	33.2925415039063
2002	33.3210601806641
2003	34.1308708190918
2004	35.3714981079102
2005	37.2755012512207
2006	39.2905006408691
2007	40.6557693481445
2008	42.2900009155273
2009	43.8448715209961
2010	45.9968490600586
2011	48.8392791748047
2012	51.904670715332
2013	53.8752784729004
2014	53.8987312316895
2015	55.7071990966797
2016	57.3460083007813
2017	58.9791603088379
2018	59.8277282714844
2019	60.4968414306641
2020	60.3850288391113