Year	% gross
1971	8.36462020874023
1972	8.45141983032227
1974	8.80344009399414
1988	17.6086196899414
1989	17.016580581665
1990	16.9349708557129
2005	20.2366504669189
2006	22.7106704711914
2007	25.1169109344482
2008	27.3560791015625
2009	28.5636501312256
2011	34.7830505371094
2012	36.362190246582
2014	37.5552101135254
2015	38.0278396606445
2016	38.0054588317871
2017	36.8902893066406
2018	36.7167587280273
2019	34.7372207641602
2021	36.2569999694824