Year	% gross
1971	16.3733406066895
1972	17.1227493286133
1973	18.4805202484131
1974	18.2847194671631
1975	18.0599994659424
1976	18.2029705047607
1977	18.9334392547607
1978	19.3370990753174
1979	19.849100112915
1980	19.5419998168945
1981	18.5667304992676
1982	18.3426208496094
1983	18.1169490814209
1984	17.3927307128906
1985	17.2207698822021
1986	16.6765003204346
1987	16.5231304168701
1988	16.5128803253174
1989	19.0891895294189
1990	18.9896793365479
1991	19.3181304931641
1992	20.5089492797852
1993	23.3708896636963
1994	26.1899394989014
1995	29.4043502807617
1996	31.5630397796631
1997	35.2004814147949
1998	39.6150283813477
1999	43.5347099304199
2000	46.3534393310547
2001	49.8890914916992
2002	53.9778289794922
2003	56.1327095031738
2004	59.6797714233398
2005	63.1373596191406
2006	66.4977798461914
2007	69.1911697387695
2008	71.5748519897461
2009	73.1574478149414
2010	74.095817565918
2011	74.9657363891602
2012	71.9028015136719
2014	68.8345565795898
2015	67.9822463989258
2016	68.6548233032227
2017	71.8307418823242
2018	67.9766311645508
2020	70.5830001831055
2021	69.2470016479492