Year	% gross
1971	30.5586700439453
1972	33.1990509033203
1973	35.5378189086914
1974	37.7276916503906
1975	39.6463508605957
1976	43.9017601013184
1977	46.5205497741699
1978	47.7955513000488
1979	49.1150093078613
1980	50.154670715332
1981	50.732349395752
1982	51.2947082519531
1983	52.4857215881348
1984	53.129508972168
1985	54.6843795776367
1986	55.423511505127
1987	54.414680480957
1988	54.1774215698242
1989	53.4754600524902
1990	53.4818305969238
1991	53.9074211120605
1992	54.8321914672852
1993	55.364429473877
1999	56.5395202636719
2000	59.6101112365723
2001	63.7311592102051
2002	67.7687377929688
2003	68.9142303466797
2004	71.5432586669922
2005	73.8731918334961
2006	76.3974304199219
2007	78.7636871337891
2008	80.4674301147461
2009	81.3888778686523
2010	81.3296966552734
2011	82.2678070068359
2012	84.3391876220703
2013	91.7803802490234
2014	91.0872268676758
2015	89.0915222167969
2016	85.3960266113281
2017	84.1052017211914