Year	% gross
1971	1.15777003765106
1972	1.27840995788574
1973	1.45659995079041
1974	1.55499994754791
1975	1.56861996650696
1976	1.84677994251251
1977	2.07311010360718
1979	2.45058989524841
1980	2.82914996147156
1981	3.04851007461548
1982	3.02480006217957
1983	3.23982000350952
1986	4.5014500617981
1987	4.61205005645752
1988	5.01126003265381
1989	5.24470996856689
1990	5.52114009857178
1991	6.03314018249512
1992	6.64688014984131
1993	6.91423988342285
1994	7.1528000831604
1995	7.44977998733521
1996	7.77443981170654
1997	8.56643009185791
1998	9.52768993377686
1999	10.0909900665283
2000	11.0357599258423
2001	11.9009504318237
2002	12.7480401992798
2003	13.5241899490356
2004	14.0115804672241
2005	15.9843502044678
2006	17.2943496704102
2007	17.0378494262695
2008	21.904670715332
2009	23.5624294281006
2010	30.1016597747803
2011	25.5266609191895
2012	25.6724090576172
2013	24.8992595672607
2014	30.1965999603271
2016	30.1551208496094
2017	29.0641899108887
2018	28.7663593292236
2019	29.2579898834229