Year	% gross
1970	100.666946411133
1971	100.804908752441
1972	100.690818786621
1973	101.383071899414
1974	100.919548034668
1975	100.84268951416
1976	100.912651062012
1977	100.52027130127
1978	100.136711120605
1979	99.274787902832
1980	101.396598815918
1981	101.174842834473
1982	101.991172790527
1983	102.015510559082
1984	101.864669799805
1985	101.679550170898
1986	101.70662689209
1987	101.667922973633
1988	101.613899230957
1989	101.678230285645
1990	101.87451171875
1991	101.63646697998
1992	101.759262084961
1993	102.18106842041
1994	102.461036682129
1995	102.604553222656
1996	102.373138427734
1997	101.147468566895
1998	101.947319030762
1999	101.707450866699
2000	101.304702758789
2001	101.455467224121
2002	101.530746459961
2003	101.589653015137
2004	102.039993286133
2005	102.227951049805
2006	102.028526306152
2007	101.900390625
2008	101.868949890137
2009	101.660507202148
2010	101.477470397949
2011	101.312492370605
2012	101.435256958008
2013	101.710632324219
2014	101.317527770996
2015	101.044296264648
2016	100.790573120117
2017	100.708038330078
2018	100.436981201172
2019	100.397857666016
2020	99.8396835327148
2021	99.6247863769531
2022	99.8471603393555