Year	% gross
1970	4.39357995986938
1971	4.37137985229492
1972	4.64509010314941
1973	4.89365005493164
1974	4.99159002304077
1975	5.33904981613159
1976	6.14438009262085
1977	6.35608005523682
1978	6.27967977523804
1979	6.16014003753662
1980	5.98185014724731
1981	5.84177017211914
1982	6.01375007629395
1983	5.59708023071289
1984	5.65790987014771
1985	5.78880977630615
1986	5.9202299118042
1987	6.11452007293701
1988	6.28565979003906
1989	6.57070016860962
1990	6.92880010604858
1991	7.66844987869263
1992	7.96671009063721
1993	8.10914039611816
1994	8.18414974212646
1995	7.95790004730225
1996	8.04154014587402
1997	8.04555988311768
1998	7.67593002319336
1999	7.39148998260498
2000	8.67543983459473
2001	9.08135032653809
2002	9.49269962310791
2003	9.95316028594971
2004	11.0672597885132
2005	10.7897500991821
2006	10.8156604766846
2007	11.7342300415039
2008	12.8950996398926
2009	13.0008096694946
2010	13.9323701858521
2011	13.9855003356934
2012	15.5484399795532
2013	14.7408103942871
2014	15.7077598571777
2015	16.4710998535156
2016	16.475040435791