Year	% gross
1971	5.185959815979
1972	2.96441006660461
1973	3.19809007644653
1974	3.32912993431091
1975	2.82176995277405
1976	2.83004999160767
1977	2.2816801071167
1978	2.50676989555359
1979	2.69180011749268
1980	2.47931003570557
1981	2.79666996002197
1982	3.17246007919312
1983	3.1631600856781
1984	2.96914005279541
1985	2.86031007766724
1986	2.99761009216309
1987	2.9466700553894
1988	3.00892996788025
1989	2.6498498916626
1990	2.85434007644653
1991	2.92865991592407
1994	2.66131997108459
1995	2.56713008880615
1996	2.5961000919342
1997	2.60873007774353
1998	2.56496000289917
1999	2.63840007781982
2000	2.10322999954224
2001	2.34758996963501
2002	2.5749499797821
2003	2.67955994606018
2004	3.03488993644714
2006	3.81292009353638
2007	4.14671993255615
2008	4.59267997741699
2009	6.98600006103516
2010	7.17675018310547
2011	9.01930999755859
2012	10.4874696731567
2013	13.4407196044922
2014	14.8092403411865
2015	17.3232002258301
2017	20.9322204589844
2018	22.5025691986084
2019	24.6073894500732
2020	29.2354793548584
2021	28.605749130249