Year	% gross
1971	6.18796014785767
1972	6.45026016235352
1973	7.13227987289429
1974	7.36286020278931
1975	8.10120010375977
1976	7.9867000579834
1977	8.22793006896973
1978	8.33463954925537
1979	8.33152008056641
1980	8.458740234375
1981	8.50792026519775
1982	8.63323020935059
1983	8.74977016448975
1984	9.18540954589844
1985	9.83368968963623
1986	10.5073299407959
1987	10.8824596405029
1988	11.2160396575928
1989	11.730770111084
1990	12.0658798217773
1991	15.1681003570557
1992	17.4066505432129
2006	24.1608905792236
2007	25.4981803894043
2008	25.6614799499512
2009	26.1832294464111
2010	25.9987106323242
2011	25.947940826416
2012	26.29248046875
2013	26.8828792572021
2014	29.0480499267578
2015	30.7594509124756
2016	32.1370811462402
2017	31.6698398590088
2018	34.239688873291
2019	36.306999206543
2021	38.201000213623