Year	% gross
1971	1.29159998893738
1972	1.52437996864319
1974	1.71972000598907
2007	6.35781002044678
2008	7.93074989318848
2009	9.71848011016846
2011	10.6684703826904
2012	10.0970697402954
2013	9.02787017822266
2016	7.81953001022339
2020	8.37246036529541