Year	% gross
1971	99.9558868408203
1972	101.017959594727
1973	102.19206237793
1974	102.555198669434
1975	103.530868530273
1976	102.525207519531
1977	102.301116943359
1978	100.387168884277
1979	98.9580764770508
1980	99.4725799560547
1981	101.633331298828
1982	103.56706237793
1983	102.110702514648
1984	101.105651855469
1985	98.2826995849609
1986	96.1517715454102
1987	96.1510391235352
1988	94.0038070678711
1989	93.31640625
1990	93.414306640625
1991	94.0902633666992
1992	96.0226135253906
1994	99.6974563598633
1995	99.7859878540039
1996	99.8133010864258
1997	100.32608795166
1998	101.21085357666
1999	100.781913757324
2000	100.814331054688
2001	99.9511337280273
2002	100.436408996582
2003	100.636520385742
2004	100.172698974609
2005	100.189918518066
2006	100.693489074707
2007	100.589630126953
2008	100.763816833496
2009	100.083892822266
2010	99.7726516723633
2011	99.6138534545898
2012	100.584167480469
2013	100.217178344727
2014	100.88117980957
2015	100.642509460449
2016	98.8811492919922
2017	98.0223617553711
2018	96.2985534667969
2019	95.9814300537109
2020	96.3843307495117
2021	101.10417175293