Year	% gross
1971	101.981903076172
1972	100.494812011719
1973	99.67626953125
1974	99.3481979370117
1975	100.582748413086
1976	100.171966552734
1977	99.6811981201172
1978	99.4200897216797
1979	99.1048278808594
1980	99.0516815185547
1981	98.8100662231445
1982	104.49292755127
1983	104.354698181152
1984	104.22794342041
1985	103.952919006348
1986	103.732437133789
1987	103.331207275391
1988	103.235328674316
1989	103.277137756348
1990	102.976661682129
1991	103.014907836914
1992	102.655578613281
1993	102.099632263184
1994	101.795143127441
1995	101.823188781738
1996	102.319442749023
1998	98.3821105957031
1999	98.7014389038086
2000	99.4177627563477
2004	99.4190063476562
2005	98.5796737670898
2006	99.7602920532227
2007	99.5356979370117
2008	98.5952835083008
2009	99.5911026000977
2010	99.1202697753906
2011	98.5558700561523
2012	99.4407119750977
2013	99.3510589599609
2014	99.4990463256836
2015	99.8411407470703
2016	98.5470275878906
2017	98.7742080688477
2018	99.0210189819336
2019	97.7884292602539
2020	97.7384185791016
2021	96.293083190918