Year	% gross
1970	9.50352001190186
1971	9.29294967651367
1972	9.15734004974365
1973	9.12059020996094
1974	9.15952014923096
1975	9.63029956817627
1976	11.6949195861816
1977	15.878270149231
1978	14.1570100784302
1979	14.2950601577759
1980	15.5107202529907
1981	17.2142391204834
1982	17.5362701416016
1983	18.5661506652832
1984	19.5429306030273
1985	21.0667591094971
1986	22.563060760498
1987	24.2121601104736
1988	25.158130645752
1989	25.0781002044678
1990	24.9954891204834
1991	24.7054500579834
1992	25.2621994018555
1993	25.5347499847412
1994	25.4860000610352
1995	26.2382106781006
1996	26.8899097442627
1997	24.9790706634521
1998	29.3406791687012
1999	30.345760345459
2000	31.6681594848633
2001	32.780330657959
2002	33.110668182373
2003	34.6150512695313
2004	36.3627586364746
2005	38.4073791503906
2006	41.1116905212402
2007	42.9691581726074
2008	45.2769508361816
2009	47.6246795654297
2010	50.1788597106934
2011	53.139030456543
2012	56.9245796203613
2013	58.8775100708008
2014	61.5405807495117
2015	63.7080307006836
2016	65.9531707763672
2017	67.8952331542969
2018	69.2652816772461
2019	70.4418487548828
2020	70.2756729125977