Year	% gross
1970	6.51918983459473
1971	6.50578022003174
1972	6.50671005249023
1973	6.48221015930176
1974	6.73941993713379
1975	7.86997985839844
1976	9.28052997589111
1977	10.0375204086304
1978	10.0261697769165
1979	10.8978004455566
1980	10.8759002685547
1981	10.6362199783325
1982	11.1919097900391
1983	11.2045202255249
1984	11.6927604675293
1985	10.7627897262573
1986	11.1223297119141
1987	11.3224201202393
1988	11.237509727478
1989	11.8293695449829
1990	12.1133403778076
1991	12.3290004730225
1992	12.4783401489258
1993	12.2470197677612
1994	12.278510093689
1995	12.3671197891235
1996	12.9470100402832
1997	13.7981996536255
1998	14.2455797195435
1999	14.3186597824097
2000	15.2516803741455
2001	15.8671598434448
2002	16.6943302154541
2003	17.7526397705078
2004	18.573709487915
2005	19.8999099731445
2006	22.2583694458008
2007	22.7088298797607
2008	23.7191791534424
2009	25.8739109039307
2010	26.3145198822021
2011	26.6968193054199
2012	26.6950702667236
2013	27.0757598876953
2014	29.8479499816895
2015	30.58616065979
2016	30.9848899841309
2017	31.5197505950928
2018	32.0594100952148
2019	33.2322196960449
2020	33.7613487243652