Year	% gross
1971	21.3324508666992
1972	25.3247394561768
1973	26.0923309326172
1974	27.1388702392578
1975	29.9542808532715
1976	31.3593292236328
1977	31.9701499938965
1978	31.9194202423096
1979	32.0635414123535
1980	31.0075702667236
1981	30.3346290588379
1983	27.5220508575439
1984	27.2276191711426
1985	27.7706909179688
1986	27.0644092559814
1987	25.8405990600586
1988	27.3178596496582
1989	28.8953304290771
1990	30.400239944458
1991	33.1659812927246
1992	33.668830871582
1993	35.162239074707
1994	38.3478698730469
1995	38.7302894592285
1996	39.2111206054688
1997	42.4001312255859
1998	41.3952484130859
1999	42.9917984008789
2000	44.0102386474609
2001	46.2518692016602
2002	48.3976516723633
2003	51.5633506774902
2004	54.3481903076172
2005	55.5750617980957
2006	56.7725105285645
2007	57.7226905822754
2008	56.358039855957
2009	55.4449882507324
2010	54.1640281677246
2011	53.1738815307617
2012	51.7420883178711
2013	51.005500793457
2014	51.2726783752441
2015	51.7670402526855
2016	52.3889007568359
2017	53.6060409545898
2018	54.8365287780762
2019	55.6776809692383
2020	57.9451599121094
2021	60.0693702697754