Year	% gross
1971	0.279449999332428
1972	0.294019997119904
1973	0.352420002222061
1974	0.38374999165535
1976	0.433160006999969
1977	0.482160001993179
1979	0.579639971256256
1980	0.645640015602112
1987	1.01503002643585
1994	1.74606001377106
1995	1.83027005195618
1997	2.9825599193573
1999	2.97550010681152
2007	5.89034986495972
2008	5.92475986480713
2009	5.65045976638794
2010	5.0619101524353
2011	2.64382004737854
2013	6.16709995269775
2014	6.10758018493652
2015	7.01909017562866
2016	7.41248989105225
2017	7.80479001998901
2019	8.58026027679443
2020	8.71506023406982