Year % gross 1970 9.05337047576904 1971 9.69221019744873 1972 10.4532098770142 1973 11.0959300994873 1974 11.7793102264404 1975 12.7924003601074 1976 13.5618696212769 1977 14.1184396743774 1978 14.7459497451782 1979 15.3120403289795 1980 15.9893102645874 1981 16.1817493438721 1982 16.8181495666504 1983 17.6784591674805 1984 18.3346004486084 1985 17.7030696868896 1986 19.3184795379639 1987 20.7122001647949 1988 21.8730907440186 1989 23.054479598999 1990 24.2187595367432 1991 25.6484603881836 1992 27.3327903747559 1993 27.979320526123 1994 28.2240505218506 1995 30.4371109008789 1996 32.7564506530762 1997 31.7470397949219 1998 33.0113105773926 1999 33.295539855957 2000 31.4077205657959 2001 33.1645393371582 2002 35.5663604736328 2003 39.9601287841797 2004 43.5407409667969 2005 46.8561897277832 2006 49.6646995544434 2007 50.3431396484375 2008 52.9987106323242 2009 55.4525718688965 2010 58.5897216796875 2011 59.4013214111328 2012 57.5912399291992 2013 58.2438583374023 2014 59.8279418945313 2015 60.9331207275391 2016 63.6871299743652 2017 66.6883697509766 2018 63.6495018005371 2019 67.9033813476563 2020 66.2236099243164