Year	% gross
1971	6.4433798789978
1972	6.43261003494263
1973	6.43744993209839
1974	6.95421981811523
1975	7.49533987045288
1976	8.02978038787842
1977	8.55568027496338
1978	9.16732025146484
1979	9.71741962432861
1980	10.3398399353027
1981	10.6734199523926
1982	11.0419597625732
1983	11.5904703140259
1984	12.0829601287842
1985	12.5861396789551
1986	13.1376895904541
1987	13.7600297927856
1988	14.3048095703125
1989	13.8052101135254
1990	13.4453001022339
1991	13.0427598953247
1992	12.5035495758057
1993	12.0015497207642
1994	11.3857002258301
1995	10.9460897445679
1996	10.6150102615356
1997	10.0685195922852
1998	11.1787204742432
1999	10.9281702041626
2000	11.2507696151733
2001	11.2585401535034
2002	11.1745700836182
2003	11.2370796203613
2004	11.4793100357056
2005	12.1333703994751
2006	12.954119682312
2007	13.5149898529053
2008	14.7893400192261
2009	15.8067302703857
2010	16.1400604248047
2011	18.3056106567383
2012	20.4868507385254
2013	21.578800201416
2014	22.1955509185791
2015	23.1248302459717
2016	24.5100193023682
2017	25.8450298309326
2018	25.8627395629883
2019	26.4809093475342
2020	27.5234909057617