Year	% gross
1971	0
1972	0
1973	0.0505900010466576
1974	0.0624900013208389
1975	0.0749699994921684
1976	0.110169999301434
1977	0.151170000433922
1978	0.150399997830391
1979	0.174779996275902
1980	0.170980006456375
1981	0.251480013132095
1982	0.315400004386902
1983	0.350410014390945
1984	0.394210010766983
1985	0.448339998722076
1987	0.492269992828369
1989	0.53218001127243
1990	0.620280027389526
1992	0.591759979724884
2003	0.809819996356964
2004	0.778509974479675
2005	0.930280029773712
2006	0.939580023288727
2007	0.888300001621246
2008	1.01989996433258
2009	1.23695003986359
2010	1.28512001037598
2011	1.33376002311707
2012	1.52788996696472
2013	2.08500003814697
2014	2.49499988555908
2015	3.43003010749817
2016	3.65476989746094
2017	3.89881992340088
2018	4.61981010437012
2019	4.43339014053345
2020	4.27199983596802