Year	% gross
1970	15.8634901046753
1971	15.6064195632935
1972	15.3918504714966
1973	15.4289798736572
1974	15.6441898345947
1975	16.2325801849365
1976	17.9617500305176
1977	20.975170135498
1978	19.7906799316406
1979	20.0182094573975
1980	21.0329494476318
1981	22.4743804931641
1982	22.8533306121826
1983	23.8174304962158
1984	24.7720108032227
1985	25.8359794616699
1986	27.1815395355225
1987	28.3979606628418
1988	29.0015106201172
1989	28.7862091064453
1990	28.7234897613525
1991	28.7322597503662
1992	28.9469699859619
1993	29.0570106506348
1994	28.9418697357178
1995	29.4166793823242
1996	29.9761009216309
1997	28.3099899291992
1998	31.4181003570557
1999	32.1182708740234
2000	33.0002288818359
2001	33.6746597290039
2002	33.5984802246094
2003	34.4588012695313
2004	35.7279014587402
2005	37.5605201721191
2006	39.5682792663574
2007	40.9783897399902
2008	42.6011581420898
2009	44.1871185302734
2010	46.2215614318848
2011	49.0010414123535
2012	52.0327301025391
2013	53.9372901916504
2014	54.0135612487793
2015	55.9540710449219
2016	57.5888481140137
2017	59.2210884094238
2018	60.0674781799316
2019	60.8039817810059
2020	60.8573989868164