Year	% gross
1971	101.619148254395
1972	101.080253601074
1973	101.432601928711
1974	101.719413757324
1975	100.689262390137
1976	100.518646240234
1977	100.053131103516
1978	99.2414321899414
1979	98.9629516601562
1980	98.8491592407227
1981	98.7873916625977
1982	99.6252136230469
1983	100.278198242188
1984	101.803810119629
1985	102.29801940918
1986	102.920791625977
1987	103.381477355957
1988	104.294647216797
1989	103.362846374512
1990	103.386581420898
1991	103.827186584473
1992	102.502738952637
1993	101.579849243164
1994	100.507720947266
1995	99.4406433105469
1996	98.9166107177734
1997	99.8091430664062
1998	101.329330444336
1999	102.274780273438
2000	103.384208679199
2001	105.242721557617
2002	106.775489807129
2003	104.64005279541
2004	102.730621337891
2005	100.15901184082
2006	99.7725601196289
2007	99.7226715087891
2008	98.912483215332
2009	98.6790771484375
2010	99.2686614990234
2011	99.5591888427734
2012	99.5789413452148
2013	101.272163391113
2014	100.961898803711
2015	99.6556701660156
2016	99.3921737670898
2017	98.4452285766602
2018	99.3739395141602
2019	100.007827758789
2020	98.8405380249023
2021	99.5407180786133
2022	99.2719802856445