Year % gross 1970 7.10710000991821 1971 7.18754005432129 1972 7.3617000579834 1973 7.50783014297485 1974 7.89662981033325 1975 8.26163005828857 1976 8.68686962127686 1977 9.17455005645752 1978 9.46776008605957 1979 9.90034961700439 1980 10.362979888916 1981 10.894700050354 1982 10.9877395629883 1983 11.7088203430176 1984 11.9792900085449 1985 12.4046697616577 1986 13.1212997436523 1987 13.4522695541382 1988 13.9596004486084 1989 13.6661796569824 1990 13.2367000579834 1991 13.3160104751587 1992 12.9964504241943 1993 12.8782596588135 1994 13.4841899871826 1995 13.5541000366211 1996 13.3909902572632 1997 9.73184967041016 1998 12.6725301742554 1999 14.6998195648193 2000 16.8578605651855 2001 18.5003795623779 2002 19.3128299713135 2003 20.8865795135498 2004 23.5234909057617 2005 26.53005027771 2006 30.4491004943848 2007 33.4790916442871 2008 36.4782981872559 2009 38.4855804443359 2010 41.6670989990234 2011 45.2207908630371 2012 47.2402114868164 2013 50.0207290649414 2014 51.7056083679199 2015 54.1528396606445 2016 56.6718482971191 2017 60.2580718994141 2018 61.0667190551758 2019 63.0017509460449 2020 62.0344886779785