Year	% gross
1970	106.417900085449
1971	106.455276489258
1972	106.45783996582
1973	105.623428344727
1974	105.170097351074
1975	104.979110717773
1976	105.463203430176
1977	104.396369934082
1978	104.036506652832
1979	103.332710266113
1980	102.849922180176
1981	102.214920043945
1982	102.351219177246
1983	102.279449462891
1984	102.175552368164
1985	102.280319213867
1986	102.318702697754
1987	102.561248779297
1988	102.065063476562
1989	101.766876220703
1990	101.269752502441
1991	100.828109741211
1992	101.179290771484
1993	102.094757080078
1994	102.678436279297
1995	102.315986633301
1996	102.695579528809
1997	102.376373291016
1998	103.524307250977
1999	103.374900817871
2000	102.649726867676
2001	103.017570495605
2002	102.905799865723
2003	102.781158447266
2004	102.597587585449
2005	103.041122436523
2006	102.887901306152
2007	102.60555267334
2008	102.182838439941
2009	101.867156982422
2010	101.574493408203
2011	101.44441986084
2012	101.428741455078
2013	102.211616516113
2014	101.517951965332
2015	101.071968078613
2016	100.990119934082
2017	101.144660949707
2018	101.08081817627
2019	101.3203125
2020	100.433151245117
2021	101.259643554688
2022	101.267112731934