Year	% gross
1971	8.35210037231445
1972	9.07946014404297
1973	9.3364200592041
1974	9.31546020507813
1975	9.44577026367188
1976	9.13226985931396
1977	8.64754962921143
1978	7.78704023361206
1979	8.40559005737305
1980	9.52140998840332
1981	10.1784801483154
1982	11.1863803863525
1983	11.9483299255371
1984	12.6023797988892
1985	14.1187000274658
1986	13.7208204269409
1987	14.8674802780151
1988	16.2417907714844
1989	16.2008895874023
1990	17.3155193328857
1991	17.8720893859863
1992	19.4510898590088
1993	20.3628902435303
1994	21.6414909362793
1995	21.7899799346924
1996	23.6773796081543
1997	25.1661605834961
1998	24.3666000366211
1999	25.5938491821289
2000	27.1518993377686
2002	28.7381191253662
2003	28.4614391326904
2004	29.0239696502686
2005	29.7686595916748
2006	30.3551406860352
2007	28.4876804351807
2008	30.4119300842285
2010	26.1557006835938
2011	26.1833305358887
2012	26.5451793670654
2013	25.6194496154785
2014	26.2603893280029
2015	25.2454299926758
2016	24.0776195526123
2017	25.792610168457
2018	27.0268402099609
2019	28.7083797454834
2020	31.4693202972412
2021	26.8109893798828