Year % gross 1970 7.4177098274231 1971 7.37342977523804 1972 7.8638801574707 1973 8.50977039337158 1974 9.06472015380859 1975 9.85597038269043 1976 10.8070201873779 1977 11.92626953125 1978 12.4900102615356 1979 12.5188703536987 1980 13.0867395401001 1981 13.8363800048828 1982 14.2580099105835 1983 14.4994802474976 1984 14.9347696304321 1985 14.8125495910645 1986 15.4631996154785 1987 15.7325801849365 1988 15.5897102355957 1989 15.1709899902344 1990 15.082200050354 1991 14.6565399169922 1992 15.4041996002197 1993 16.3342800140381 1994 17.0092391967773 1995 17.8907108306885 1996 19.2875308990479 1997 20.0223693847656 1998 20.5941104888916 1999 21.5076599121094 2000 21.3771800994873 2001 21.5592002868652 2002 21.6042194366455 2003 21.2276401519775 2004 22.6563091278076 2005 23.4961204528809 2006 24.0956592559814 2007 25.9120292663574 2008 27.0835704803467 2009 28.2250595092773 2010 30.1028308868408 2011 30.048770904541 2012 31.8204097747803 2013 33.4578704833984 2014 36.0429306030273 2015 38.4878311157227 2016 37.2616195678711 2017 37.685359954834 2018 37.5310401916504 2019 37.5997581481934 2020 37.6245918273926 2021 37.5107803344727 2022 37.3423194885254