Year	% gross
1970	17.7437305450439
1971	18.3138809204102
1972	19.8351097106934
1973	19.9622097015381
1974	21.7914295196533
1975	23.8893394470215
1976	25.9989490509033
1977	29.6623001098633
1978	27.0586700439453
1979	29.4854202270508
1980	36.2196502685547
1982	33.3081398010254
1983	37.0756912231445
1984	32.6817283630371
1985	28.3463897705078
1986	29.2909603118896
1987	31.7915592193604
1988	31.7397708892822
1989	31.1931896209717
1990	34.6021995544434
1991	40.4760093688965
1992	40.7747917175293
1993	41.5942306518555
1994	42.5326881408691
1995	44.4172096252441
1998	46.1412010192871
1999	51.2359886169434
2000	52.7258491516113
2001	55.628791809082
2002	59.805908203125
2004	64.1583480834961
2005	66.9869766235352
2006	66.5023880004883
2007	69.1894378662109
2008	67.561653137207
2010	67.9309005737305