Year	% gross
1971	108.137680053711
1972	106.587623596191
1973	106.717872619629
1974	104.667427062988
1975	104.495429992676
1976	103.826782226562
1977	103.058700561523
1978	102.525917053223
1979	101.424407958984
1980	100.964172363281
1981	100.678718566895
1982	100.800567626953
1983	101.23609161377
1984	101.495979309082
1985	102.10774230957
1986	101.879371643066
1987	101.698822021484
1988	102.07795715332
1989	102.823951721191
1990	103.831169128418
1991	104.478851318359
1992	104.649391174316
1993	105.671112060547
1994	105.763877868652
1995	106.010459899902
1996	105.120010375977
1997	79.8163909912109
1998	102.668952941895
1999	101.463111877441
2000	101.59252166748
2001	101.579086303711
2002	102.570167541504
2003	102.302886962891
2004	102.533767700195
2005	102.882858276367
2006	102.722717285156
2007	102.796333312988
2008	102.223648071289
2009	102.656272888184
2010	103.279571533203
2011	103.319938659668
2012	102.12336730957
2013	101.767791748047
2014	101.320182800293
2015	100.977363586426
2016	101.042961120605
2017	100.694290161133
2018	100.770469665527
2019	100.929656982422
2020	101.187568664551
2021	100.570220947266