Year	% gross
1970	17.9943599700928
1971	18.0324401855469
1972	18.8360004425049
1973	19.8289699554443
1974	20.4936504364014
1975	21.4252891540527
1976	22.7137603759766
1977	23.4043197631836
1978	24.1129703521729
1979	24.0465602874756
1980	24.4779796600342
1981	24.6529808044434
1982	24.9480495452881
1983	25.0271606445312
1984	25.4034996032715
1985	25.9926204681396
1986	26.4395503997803
1987	26.6097297668457
1988	27.2556896209717
1989	28.3955402374268
1990	29.3689804077148
1991	30.970760345459
1992	32.5444602966309
1993	35.1210784912109
1994	38.0570106506348
1995	39.6536293029785
1996	41.7627792358398
1997	43.8586387634277
1998	44.9949417114258
1999	46.9803314208984
2000	48.7897415161133
2001	51.3767509460449
2002	53.8632392883301
2003	56.2855911254883
2004	58.4711799621582
2005	60.2478790283203
2006	61.6573486328125
2007	62.5128288269043
2008	63.7148590087891
2009	64.9656600952148
2010	66.4165191650391
2011	67.2159576416016
2012	67.2255935668945
2013	67.500617980957
2014	68.6604690551758
2015	69.6855392456055
2016	70.3927917480469
2017	71.6794281005859
2018	72.7852935791016
2019	73.8699188232422
2020	74.7346878051758
2021	77.3375015258789
2022	77.4991073608398