Year % gross 1970 7.07630014419556 1971 7.21681022644043 1972 7.36501979827881 1973 7.52514982223511 1974 7.83905982971191 1975 8.5538501739502 1976 9.15590953826904 1977 9.79837989807129 1978 10.2369203567505 1979 10.793740272522 1980 11.3653497695923 1981 12.0563402175903 1982 12.9095497131348 1983 13.496190071106 1984 14.0818099975586 1985 14.5117902755737 1986 15.2581100463867 1987 15.7394599914551 1988 16.3515605926514 1989 16.3143291473389 1990 16.1234703063965 1991 16.6616592407227 1992 16.6178493499756 1993 16.5965805053711 1994 16.9967403411865 1995 17.3620300292969 1996 17.5974292755127 1997 14.5725202560425 1998 16.7064094543457 1999 17.7555294036865 2000 19.5729503631592 2001 20.9568691253662 2002 22.0895309448242 2003 23.4727306365967 2004 25.4615497589111 2005 28.1101207733154 2006 31.6274108886719 2007 34.3412895202637 2008 36.7509307861328 2009 38.7772102355957 2010 40.7975311279297 2011 43.2825317382813 2012 45.7615699768066 2013 47.3437385559082 2014 49.1729202270508 2015 51.2425498962402 2016 52.7068786621094 2017 54.8920516967773 2018 55.7059898376465 2019 56.8959808349609 2020 55.701530456543