Year	% gross
1971	36.7592391967773
1972	37.6164398193359
1973	39.0448684692383
1974	41.9088516235352
1975	44.5367584228516
1976	46.2019386291504
1977	47.580020904541
1978	50.2522888183594
1979	54.8440093994141
1980	57.3958282470703
1981	59.141918182373
1982	58.3409690856934
1983	55.7282409667969
1984	54.533561706543
1985	55.2162704467773
1986	55.0046501159668
1987	55.2584114074707
1988	57.4689292907715
1989	60.5586891174316
1990	61.5405616760254
1991	55.9936218261719
1992	54.0858497619629
1993	53.0632591247559
1994	49.0806007385254
1995	51.1218414306641
1996	52.2091484069824
1997	53.815990447998
1998	57.5222282409668
1999	66.0752716064453
2000	69.5179824829102
2001	72.8236083984375
2002	73.9380416870117
2003	73.790153503418
2004	72.2249298095703
2005	74.2329864501953
2006	75.3997116088867
2007	76.35888671875
2008	77.7559127807617
2009	79.1811599731445
2010	80.2928314208984
2011	80.6949691772461
2012	79.3038482666016
2013	88.3197631835938
2014	84.9904174804688
2015	85.066780090332
2016	82.8454971313477
2017	83.9636611938477
2018	88.3221893310547
2019	93.6755218505859
2020	94.9140777587891