Year	% gross
1971	1.34402000904083
1972	1.51076996326447
1973	1.68261003494263
1974	1.96878004074097
1975	2.11526989936829
1976	2.38725996017456
1977	2.87632989883423
1978	3.43822002410889
1979	4.15256023406982
1980	4.8130898475647
1981	5.50269985198975
1988	7.01430988311768
1989	7.59572982788086
1990	7.69635009765625
1991	8.3317403793335
1992	7.96009016036987
1993	7.72727012634277
1996	7.81542015075684
1997	7.84091997146606
1998	7.54972982406616
1999	7.60528993606567
2000	7.40724992752075
2001	7.31929016113281
2002	7.44751977920532
2003	8.1004695892334
2004	9.93025016784668
2005	10.939510345459
2006	12.694239616394
2007	12.3654003143311
2008	12.8714799880981
2009	13.5576496124268
2010	14.8534097671509
2011	16.175329208374
2012	17.2857704162598
2013	19.6701602935791
2014	21.7561092376709
2015	24.0136394500732
2016	27.4477691650391
2017	28.9340896606445