Year	% gross
1971	0.960430026054382
1972	1.18819999694824
1973	1.46796000003815
1974	1.73301994800568
1975	1.90600001811981
2002	6.27102994918823
2003	6.32882022857666
2004	6.3188099861145
2005	7.19714021682739
2006	8.09924983978271
2007	8.33730030059814
2008	8.99761009216309
2009	10.3250904083252
2010	12.5340995788574
2011	14.1592702865601
2012	14.9979496002197
2013	17.4658107757568
2014	18.5039691925049
2015	18.8671798706055
2016	13.2913799285889
2017	14.1059999465942
2018	15.2198495864868