Year	% gross
1970	17.325439453125
1971	17.6602096557617
1972	18.3764705657959
1973	18.7131500244141
1974	19.7091102600098
1975	20.8267307281494
1976	22.8783397674561
1977	23.2531108856201
1978	24.7152690887451
1979	25.4091205596924
1980	28.0641708374023
1981	27.3535900115967
1982	27.3246994018555
1983	28.6093597412109
1984	30.1341094970703
1985	37.6873512268066
1986	37.5152893066406
1987	39.9140701293945
1988	39.7036209106445
1999	39.6874618530273
2000	40.3647918701172
2001	41.158561706543
2002	41.428539276123
2003	43.2558097839355
2004	46.9004898071289
2005	47.1551094055176
2006	48.7971496582031
2007	50.9123115539551
2008	57.1344604492188
2009	57.8705596923828