Year	% gross
1973	17.196310043335
1974	17.5491008758545
1975	17.9232597351074
1976	18.2413501739502
1977	18.600830078125
1978	19.0781192779541
1979	19.4906406402588
1980	19.9430599212646
1981	20.1611595153809
1982	20.4360694885254
1983	20.9283008575439
1984	21.3383598327637
1985	21.7302894592285
1986	22.2084503173828
1987	22.7069702148438
1988	23.184440612793
1989	22.9943599700928
1990	22.8750190734863
1991	22.7153396606445
1992	22.3423004150391
1993	21.7800998687744
1994	21.2443904876709
1995	20.8337802886963
1996	20.6624603271484
1997	19.7174205780029
1998	19.6185092926025
1999	18.9444694519043
2000	19.2300701141357
2001	18.5591697692871
2002	17.5115604400635
2003	17.4314193725586
2004	18.5071601867676
2005	19.4969100952148
2006	22.0451107025146
2007	23.3925094604492
2008	24.3179893493652
2009	24.917610168457
2010	25.9155197143555
2011	28.604679107666
2012	30.9350299835205
2013	33.1581687927246
2014	28.9310092926025
2015	30.4857597351074
2016	31.5197200775146
2017	33.3090591430664
2018	33.9285011291504
2019	34.4763488769531
2020	35.5681686401367