Year	% gross
1972	7.29711008071899
1973	7.36766004562378
1974	7.45421981811523
1975	7.57815980911255
1976	7.69680976867676
1977	7.76310014724731
1978	7.84637022018433
1979	7.97634983062744
1980	8.01375007629395
1981	7.9641900062561
1982	8.01883029937744
1983	7.92154979705811
1984	7.84299993515015
1985	7.89965009689331
1986	7.92893981933594
1990	8.24349975585938
1991	8.18325996398926
1992	8.07544994354248
1993	8.01414966583252
1994	7.79455995559692
1995	7.70743989944458
1996	7.7059497833252
1997	7.64884996414185
1998	7.8882098197937
1999	7.99398994445801
2000	8.22850036621094
2001	8.35284996032715
2002	8.56700038909912
2003	9.00691986083984
2004	9.21837043762207
2005	9.49234962463379
2006	9.89577007293701
2007	10.1839599609375
2008	10.8976602554321
2009	11.5737895965576
2010	11.4890804290771
2011	11.9498300552368
2012	14.1658802032471
2013	15.4975700378418
2014	16.152250289917
2015	17.2766895294189
2016	18.0356197357178
2017	18.949649810791
2018	19.367259979248
2019	19.8421897888184
2020	20.1812191009521