Year % gross 1970 3.22213006019592 1971 3.26454997062683 1972 3.54350996017456 1973 3.89434003829956 1974 4.21263980865479 1975 4.65739011764526 1976 5.21875 1977 5.60575008392334 1978 5.98786020278931 1979 6.26506996154785 1980 6.70663022994995 1981 7.22821998596191 1982 7.59732007980347 1983 7.83086013793945 1984 8.12650966644287 1985 8.27830982208252 1986 8.45139026641846 1987 8.6200704574585 1988 9.20205974578857 1989 9.2367000579834 1990 9.5522403717041 1991 9.58102035522461 1992 10.2586002349854 1993 11.0664796829224 1994 11.6760702133179 1995 12.4320297241211 1996 13.5900497436523 1997 14.665379524231 1998 15.6186199188232 1999 16.889289855957 2000 17.3863201141357 2001 18.2983798980713 2002 19.0069808959961 2003 19.6849403381348 2004 20.8828392028809 2005 22.2404003143311 2006 23.6521091461182 2007 25.1959705352783 2008 28.4735698699951 2009 28.6965007781982 2010 30.1706199645996 2011 30.6674709320068 2012 32.5156402587891 2013 33.4278793334961 2014 35.6032104492188 2015 37.8225517272949 2016 37.8533515930176 2017 38.1584892272949 2018 39.1791305541992 2019 39.4493713378906 2020 39.6533088684082 2021 39.8545608520508 2022 40.2422294616699