Year	% gross
1971	9.02320003509521
1972	8.80008029937744
1973	11.8641595840454
1974	13.4284000396729
1975	6.82964992523193
1976	8.95804023742676
1977	11.5897798538208
1978	12.6873502731323
1979	14.9088201522827
1980	19.685510635376
1981	23.0455493927002
1982	25.0054206848145
1983	26.4850902557373
1984	29.489429473877
1985	32.7919502258301
1986	34.7845916748047
1987	34.2769317626953
1988	37.2979507446289
1989	37.6238403320313
1990	39.9985504150391
1991	42.2548789978027
1992	44.2084808349609
1993	59.078010559082
1994	59.0675010681152
1995	59.4113883972168
1996	60.1810913085938
1997	60.1091384887695
1999	59.8071708679199
2000	56.9777793884277
2001	59.7128715515137
2002	59.2480087280273
2003	59.6447410583496
2004	60.7317314147949
2005	64.758056640625
2006	78.7588195800781
2007	79.6286468505859
2008	82.6405181884766
2009	80.5135726928711
2010	79.0906372070313
2011	79.4582214355469
2012	77.9245529174805
2013	78.5376968383789
2014	77.1095809936523
2015	80.2753067016602
2016	81.4167327880859
2017	83.7125930786133
2018	85.3430862426758
2019	87.1440277099609
2020	86.661247253418
