Year	% gross
1971	100.407653808594
1972	96.1614532470703
1973	91.5302810668945
1974	87.1983795166016
1975	89.3445587158203
1976	89.9824676513672
1977	92.5731887817383
1978	92.7283096313477
1979	93.6073684692383
1980	95.9493179321289
1981	98.3873596191406
1982	103.260726928711
1983	106.320259094238
1984	105.402153015137
1985	106.430633544922
1986	108.278930664062
1987	106.874870300293
1988	108.892997741699
1989	111.52668762207
1990	112.059669494629
1991	107.283828735352
1992	105.00203704834
1993	101.529388427734
1994	103.372482299805
1995	99.711181640625
1996	99.0324096679688
1997	99.6525192260742
1998	104.943069458008
1999	104.47435760498
2000	101.851333618164
2001	94.3836669921875
2002	95.1474914550781
2003	96.9064788818359
2004	93.3679122924805
2005	96.1018829345703
2006	94.6122207641602
2007	98.2639617919922
2008	98.5704574584961
2009	103.211761474609
2010	103.012962341309
2011	99.2632522583008
2012	102.537559509277
2013	100.88224029541
2014	98.5980987548828
2015	101.982368469238
2016	104.046173095703
2017	106.431632995605
2018	107.334487915039
2019	103.579849243164
2020	102.090957641602