Year	% gross
1970	100.521781921387
1971	100.583808898926
1972	100.569229125977
1973	101.54109954834
1974	101.138748168945
1975	101.222953796387
1976	101.443046569824
1977	101.01496887207
1978	100.725730895996
1979	99.9847869873047
1980	102.482147216797
1981	102.381591796875
1982	103.428298950195
1983	103.624801635742
1984	103.59831237793
1985	103.435852050781
1986	103.552383422852
1987	103.493759155273
1988	103.601867675781
1989	103.671699523926
1990	103.962379455566
1991	103.866493225098
1992	103.949058532715
1993	104.264198303223
1994	104.497001647949
1995	104.539329528809
1996	104.11213684082
1997	103.329650878906
1998	103.264808654785
1999	102.993240356445
2000	102.547660827637
2001	102.785911560059
2002	102.966941833496
2003	102.279289245605
2004	102.568550109863
2005	103.028427124023
2006	102.658683776855
2007	102.46354675293
2008	102.384918212891
2009	102.067596435547
2010	101.670913696289
2011	101.369911193848
2012	101.247901916504
2013	101.313789367676
2014	100.821380615234
2015	100.770500183105
2016	100.924392700195
2017	101.187690734863
2018	100.988067626953
2019	100.972801208496
2020	100.658737182617
2021	99.9837493896484
2022	99.9626312255859