Year	% gross
1971	77.7733383178711
1972	82.3743896484375
1973	85.902717590332
1974	88.0361633300781
1975	89.8753204345703
1976	92.9874725341797
1977	91.2875289916992
1978	80.0567779541016
1979	82.4121780395508
1980	93.4376602172852
1981	93.8656463623047
1982	92.9498596191406
1983	92.7470321655273
1984	94.0912475585938
1999	71.087532043457
2001	79.2035903930664
2002	83.5448989868164
2003	86.5518112182617
2004	85.3811798095703
2005	87.2894668579102
2006	87.3909912109375
2007	86.3398590087891
2008	86.4051666259766
2010	89.0047988891602
2011	88.7627182006836
2012	93.4414672851563
2013	93.8949127197266
2014	93.5591735839844
2015	91.8645629882813
2016	92.1733322143555
2017	90.834342956543
2018	90.8428115844727
2019	91.6517868041992
2020	91.9821624755859