Year % gross 1970 14.3238201141357 1971 14.4764995574951 1972 14.9720802307129 1973 15.2534704208374 1974 15.4209604263306 1975 16.2325992584229 1976 16.9654197692871 1977 17.9015007019043 1978 18.7857799530029 1979 19.7335605621338 1980 20.6401805877686 1981 21.5055904388428 1982 21.7173194885254 1983 22.2082996368408 1984 22.2804298400879 1985 22.0200805664062 1986 21.7647094726562 1987 21.6747608184814 1988 22.0807094573975 1989 21.6612606048584 1990 21.5043296813965 1991 21.6629009246826 1992 21.4082107543945 1993 21.461799621582 1994 22.0818099975586 1995 22.2208194732666 1996 22.3298397064209 1997 22.5096492767334 1998 23.4176292419434 1999 24.1695404052734 2000 24.8393898010254 2001 26.0861206054688 2002 27.0782508850098 2003 27.9791507720947 2004 29.8299407958984 2005 31.2478008270264 2006 33.2465782165527 2007 34.9876098632812 2008 37.1389617919922 2009 38.8503913879395 2010 40.4840507507324 2011 41.4388084411621 2012 42.4207496643066 2013 43.2207984924316 2014 43.4917602539062 2015 43.3271217346191 2016 43.6524810791016 2017 43.7959785461426 2018 44.1782188415527 2019 44.3122100830078 2020 44.517650604248 2021 44.5803489685059 2022 44.2253608703613