Year	% gross
1970	100.042778015137
1971	100.22241973877
1972	100.137840270996
1973	101.05982208252
1974	100.343887329102
1975	100.289680480957
1976	100.618698120117
1977	99.9944381713867
1978	99.6652526855469
1979	98.7572784423828
1980	100.937438964844
1981	100.73136138916
1982	101.465408325195
1983	101.281936645508
1984	101.259689331055
1985	101.152610778809
1986	101.090476989746
1987	100.900108337402
1988	100.832778930664
1989	100.968910217285
1990	101.293426513672
1991	100.921821594238
1992	101.034896850586
1993	101.418128967285
1994	101.813209533691
1995	101.894142150879
1996	101.61644744873
1997	100.693199157715
1998	101.763603210449
1999	101.551368713379
2000	101.176872253418
2001	101.236396789551
2002	101.184257507324
2003	101.190902709961
2004	101.562210083008
2005	101.740570068359
2006	101.609817504883
2007	101.524391174316
2008	101.469390869141
2009	101.289390563965
2010	101.183776855469
2011	101.053413391113
2012	101.23307800293
2013	101.476341247559
2014	101.142127990723
2015	100.984756469727
2016	100.730308532715
2017	100.539970397949
2018	100.372039794922
2019	100.543716430664
2020	99.722038269043
2021	99.5807876586914
2022	99.8431167602539