Year	% gross
1970	0.165830001235008
1971	0.189909994602203
1972	0.222430005669594
1974	0.202900007367134
1975	0.18367999792099
1976	0.184530004858971
1977	0.283690005540848
1979	0.252429991960526
1980	0.216940000653267
1981	0.241750001907349
1982	0.309130012989044
1985	0.334479987621307
1986	0.425460010766983
1988	0.506500005722046
1989	0.494219988584518
1990	0.580919981002808
1991	0.664600014686584
1992	0.673229992389679
1993	0.766860008239746
1994	0.90363997220993
1995	0.998560011386871
1996	1.16870999336243
1999	1.33159995079041
2000	1.75007998943329
2001	1.94625997543335
2002	2.69584989547729
2003	2.8102400302887
2004	2.78060007095337
2006	3.04973006248474
2008	3.33209991455078
2009	3.66866993904114
2010	3.40527009963989
2011	3.77489995956421
2012	3.1066300868988
2013	3.44600009918213
2014	3.96725010871887
2015	4.3270001411438
2016	4.16099977493286