Year	% gross
1970	7.8020601272583
1971	7.75257015228271
1972	7.67741012573242
1973	7.59802007675171
1974	7.49987983703613
1975	7.46503019332886
1976	7.50304985046387
1977	7.68912982940674
1978	7.87873983383179
1979	7.96124982833862
1980	8.02470970153809
1981	8.07563018798828
1982	8.06659984588623
1983	8.02886962890625
1984	8.06066036224365
1985	8.04399967193604
1986	8.10791015625
1987	8.40647983551025
1988	8.29335021972656
1989	8.26012992858887
1990	8.33532047271729
1991	8.25860023498535
1992	8.13949012756348
1993	8.09370994567871
1994	7.9417200088501
1995	8.08022022247314
1996	8.16485977172852
1997	8.40530967712402
1998	8.67138957977295
1999	9.1561803817749
2000	9.52252960205078
2001	10.3192901611328
2002	10.9742298126221
2003	11.4438600540161
2004	12.0738697052002
2005	13.0219202041626
2006	13.9066200256348
2007	14.5480098724365
2008	15.3373498916626
2009	15.4911298751831
2010	15.4631795883179
2011	15.3546304702759
2012	15.1009998321533
2013	14.9833498001099
2014	15.0814695358276
2015	14.6258096694946
2016	14.3706197738647
2017	14.3576602935791
2018	14.3072004318237
2019	14.150110244751