Year	% gross
1971	100.106086730957
1972	101.957977294922
1973	102.722831726074
1974	102.674819946289
1975	102.212028503418
1976	102.461959838867
1977	100.202362060547
1978	99.2359619140625
1979	100.010139465332
1980	100.493370056152
1981	101.760276794434
1982	102.897888183594
1983	103.71524810791
1984	103.238571166992
1985	102.402671813965
1986	100.26286315918
1987	99.1139984130859
1988	97.2687911987305
1989	96.9967193603516
1990	98.298957824707
1991	98.8888778686523
1992	100.737159729004
1993	101.66374206543
1994	103.078842163086
1995	103.151412963867
1996	102.481750488281
1997	100.298080444336
1998	100.59822845459
1999	101.044090270996
2000	98.9645385742188
2001	98.7921524047852
2002	98.9580383300781
2003	99.9939575195312
2004	100.176528930664
2005	100.344917297363
2006	100.363288879395
2007	100.793983459473
2008	101.344970703125
2009	101.050827026367
2010	100.80436706543
2011	100.998878479004
2012	101.147590637207
2013	100.268768310547
2014	99.4568099975586
2015	100.062088012695
2016	99.7160110473633
2017	98.6247100830078
2018	98.6656723022461
2019	99.6388168334961
2020	99.217903137207
2021	98.67578125
2022	99.0333633422852