Year % gross 1971 14.2488098144531 1972 14.7389497756958 1973 15.9600095748901 1974 16.1713905334473 1975 16.309549331665 1976 16.3923492431641 1977 16.4106597900391 1978 16.3283100128174 1979 15.1938695907593 1980 14.4281797409058 1981 13.9812602996826 1982 14.2727899551392 1983 14.239330291748 1984 14.709059715271 1985 15.7238702774048 1986 17.0328693389893 1987 18.2308197021484 1988 19.3945503234863 1989 22.0102500915527 1990 23.6670207977295 1991 28.8909091949463 1992 27.6483497619629 1993 26.6125602722168 1994 26.9698104858398 1995 27.7539005279541 1996 29.653299331665 1997 31.8652095794678 1998 32.4690589904785 1999 35.199031829834 2000 35.298770904541 2001 34.951961517334 2002 37.0724411010742 2003 39.2500915527344 2004 40.2176513671875 2005 42.8675689697266 2006 43.0832214355469 2007 45.9975318908691 2008 45.5848197937012 2009 47.4323883056641 2010 50.4553298950195 2011 52.1960716247559 2012 54.7837600708008 2013 57.7969398498535 2014 61.8012008666992 2015 65.2734985351562 2016 67.3981781005859 2017 68.1936874389648 2018 68.4603500366211 2019 67.2740783691406 2020 66.5341110229492 2021 65.565559387207