Year	% gross
1971	3.16782999038696
1972	3.49981999397278
1973	3.809809923172
1974	4.10231018066406
1975	4.3810601234436
1976	4.64925003051758
1977	4.85912990570068
1978	5.03613996505737
1979	6.28510999679565
1980	6.80719995498657
1981	7.29771995544434
1982	6.89765977859497
1983	6.83862018585205
1984	8.91485977172852
1985	10.4958400726318
1986	11.0113296508789
1987	12.0867900848389
1988	12.5968503952026
1989	12.2228899002075
1990	11.9682197570801
1991	11.7549896240234
1992	11.4359502792358
1993	11.1139802932739
1994	10.5332298278809
1995	10.3259601593018
1997	9.50664043426514
1998	9.802490234375
1999	10.9266996383667
2000	12.6780195236206
2001	12.8380603790283
2002	13.2329196929932
2003	13.5788803100586
2004	16.8585605621338
2005	18.1327209472656
2006	17.8521595001221
2007	19.2424297332764
2008	22.5884304046631
2009	23.8425693511963
2010	25.4624004364014
2011	26.6580505371094
2012	29.6590805053711
2013	31.8525390625
2014	33.8789901733398
2015	37.0492286682129
2016	38.6550712585449
2017	35.8837394714355
2018	34.4643402099609
2019	35.6178703308105