Year	% gross
1971	91.2010192871094
1972	91.8884124755859
1973	92.6170883178711
1974	93.9875030517578
1975	94.9200210571289
1976	89.9315719604492
1977	92.382942199707
1978	90.7652587890625
1979	88.5028381347656
1980	87.833137512207
1981	87.1987075805664
1982	87.6037902832031
1983	88.8856506347656
1984	89.9869003295898
1985	91.476806640625
1986	96.5484390258789
1987	99.154411315918
1988	102.173110961914
1989	103.60408782959
1990	100.589660644531
1991	98.9886322021484
1992	96.7985000610352
1993	94.4385223388672
1994	91.5175094604492
1995	92.9497604370117
1996	93.2075576782227
1997	92.3336715698242
1998	91.3241119384766
1999	79.2764282226562
2000	79.8759078979492
2001	80.9440765380859
2002	83.9819869995117
2003	88.118782043457
2004	90.5342712402344
2005	91.3667678833008
2006	92.4120101928711
2007	93.1541595458984
2008	92.3840713500977
2009	92.5213775634766
2010	94.1819229125977
2011	96.4361267089844
2012	95.3903503417969
2013	101.152542114258
2014	103.013290405273
2015	100.060470581055
2016	97.3430328369141
2017	95.7457427978516
2018	95.3189697265625
2019	93.5191802978516
2020	91.2799377441406
2021	89.7356414794922