Year	% gross
1971	15.5745496749878
1972	16.3423004150391
1973	18.4807605743408
1974	20.0688705444336
1975	21.7554702758789
1976	21.8385200500488
1977	23.4681491851807
1978	26.1704406738281
1979	28.6527500152588
1980	31.3620700836182
1981	33.8559188842773
1982	35.8459091186523
1983	34.7328300476074
1984	33.6747512817383
1985	35.0832405090332
1986	35.9495582580566
1987	35.4831008911133
1988	35.2235984802246
1989	35.0856513977051
1993	32.8283805847168
1996	29.8814907073975
1999	26.1967296600342
2000	27.8185596466064
2001	27.4438591003418
2003	33.4032096862793
2004	35.8993301391602
2007	42.6503105163574