Year	% gross
1971	101.81559753418
1972	99.3229293823242
1973	97.1286697387695
1974	94.8334274291992
1975	91.8711471557617
1976	92.1315994262695
1977	92.0663681030273
1978	93.3143997192383
1979	93.6474990844727
1980	94.8815078735352
1981	96.7041702270508
1982	99.7978897094727
1983	101.412750244141
1984	102.756172180176
1985	104.543487548828
1986	105.012176513672
1987	107.789093017578
1988	107.71923828125
1989	106.760208129883
1990	99.4779815673828
1991	97.5340881347656
1992	95.8859329223633
1993	95.2511215209961
1994	95.0588531494141
1995	96.9171371459961
1996	100.272453308105
1997	101.54483795166
1998	103.443321228027
1999	105.137008666992
2000	104.70467376709
2001	105.339256286621
2002	109.646987915039
2003	111.694488525391
2004	111.75122833252
2005	110.920433044434
2006	108.823188781738
2007	106.104972839355
2008	104.157562255859
2009	102.061912536621
2010	101.400619506836
2011	101.120269775391
2012	100.363082885742
2013	99.5608215332031
2014	99.7107009887695
2015	98.7655868530273
2016	96.8762893676758
2017	95.1726913452148
2018	93.6309509277344
2019	91.1833114624023
2020	88.9717636108398
2021	87.2791290283203
