Year	% gross
1971	15.09202003479
1972	15.1006002426147
1973	15.5555696487427
1974	15.8375701904297
1975	16.6953392028809
1976	16.6267395019531
1977	16.7152805328369
1978	16.7520809173584
1979	15.4925498962402
1980	15.9938802719116
1981	16.0475292205811
1982	16.2279796600342
1983	17.0569305419922
1984	17.8578701019287
1985	18.7081909179688
1986	18.8718109130859
1987	19.2109909057617
1988	19.4664402008057
1989	20.1443004608154
1990	20.7386207580566
1991	23.7177505493164
1992	26.3336696624756
2003	19.9118404388428
2004	21.908519744873
2005	22.8122806549072
2006	27.5696792602539
2007	29.4775695800781
2008	29.6895599365234
2009	29.5907192230225
2010	29.8961391448975
2011	30.3576793670654
2012	31.2602005004883
2013	32.1165084838867
2014	33.2142181396484
2015	35.1742515563965
2016	36.3533706665039
2017	35.8526802062988
2018	37.74951171875
2019	39.6166496276855
2021	41.8549995422363