Year	% gross
1971	17.1944599151611
1972	17.5277900695801
1973	17.3701305389404
1974	17.456579208374
1975	16.4977207183838
1976	16.9836502075195
1977	17.4380893707275
1978	20.28005027771
1979	23.2412109375
1980	24.0281105041504
1981	25.4379806518555
1982	26.0764102935791
1983	26.9976902008057
1984	29.5400199890137
1985	28.3261909484863
1986	25.1323204040527
1987	23.7229194641113
1988	24.8065204620361
1989	26.037109375
1990	24.3191394805908
1991	26.8433494567871
1992	25.6675891876221
1995	27.3833103179932
1996	28.7979202270508
1998	27.224479675293
1999	28.4981307983398
2001	30.4657897949219
2002	30.6726207733154
2003	29.875
2004	29.3516693115234
2005	28.5942401885986
2006	28.8363800048828
2008	29.071460723877
2009	28.1930503845215
2010	29.4099998474121
2011	30.826000213623
2012	31.3090000152588
2013	33.7900009155273
2014	35.9550018310547
2015	38.1040000915527
2016	40.4860000610352
2017	35.4049987792969
2018	29.4290008544922
2019	31.2369995117188
2020	32.8470001220703
2021	34.890998840332