Year % gross 1970 7.51266002655029 1971 7.46509981155396 1972 7.95066976547241 1973 8.58957004547119 1974 9.13953018188477 1975 9.9240198135376 1976 10.8673801422119 1977 11.9771299362183 1978 12.5362100601196 1979 12.5647497177124 1980 13.1274995803833 1981 13.8703098297119 1982 14.2876100540161 1983 14.5270395278931 1984 14.9587602615356 1985 14.837869644165 1986 15.4826898574829 1987 15.7496995925903 1988 15.6087398529053 1989 15.193920135498 1990 15.1059999465942 1991 14.6843099594116 1992 15.4252195358276 1993 16.3465595245361 1994 17.0150203704834 1995 17.8875904083252 1996 19.2701206207275 1997 20.0235805511475 1998 20.6089191436768 1999 21.537130355835 2000 21.4128799438477 2001 21.6114807128906 2002 21.6722106933594 2003 21.3301792144775 2004 22.7863807678223 2005 23.6546993255615 2006 24.2435607910156 2007 26.07008934021 2008 27.2446098327637 2009 28.3486309051514 2010 30.2200508117676 2011 30.1878700256348 2012 31.9289608001709 2013 33.5098991394043 2014 36.0457382202148 2015 38.465690612793 2016 37.2435302734375 2017 37.6553115844727 2018 37.5200881958008 2019 37.5630302429199 2020 37.5796890258789 2021 37.4486083984375 2022 37.3015213012695