Year	% gross
1970	4.05115985870361
1971	3.83990001678467
1972	4.90278005599976
1973	4.32104015350342
1974	4.8155198097229
1975	6.53117990493774
1976	7.3092098236084
1977	7.15558004379272
1979	8.66005992889404
1980	10.980110168457
1982	9.66294956207275
1983	10.1967000961304
1984	8.86474990844727
1985	7.90799999237061
1986	7.10903978347778
1987	6.93101978302002
1990	7.1426100730896
1991	7.05389976501465
1992	7.71009016036987
1995	9.93037033081055
1997	10.2328500747681
2002	17.7272491455078
2010	15.4230003356934
2011	15.8640003204346
2012	16.4950008392334
2013	16.3549995422363
2014	17.1520004272461
2015	17.3419990539551
2016	17.7749996185303
2018	19.3090000152588
2019	17.7679996490479
2020	18.6860008239746
2021	19.8999996185303