Year % gross 1970 5.86393022537231 1971 5.87080001831055 1972 5.93215990066528 1973 6.03820991516113 1974 6.21709012985229 1975 6.45925998687744 1976 6.72237014770508 1977 6.84795999526978 1978 7.04591989517212 1979 7.42182016372681 1980 7.73746013641357 1981 8.01863956451416 1982 7.99149990081787 1983 8.03462028503418 1984 8.08981037139893 1985 8.08378982543945 1986 8.31134033203125 1987 8.47776985168457 1988 8.32419013977051 1989 8.37913990020752 1990 8.42444038391113 1991 8.45936012268066 1992 8.46767997741699 1993 8.57999992370605 1994 9.0272798538208 1995 9.48318958282471 1996 10.2017803192139 1997 10.9123296737671 1998 11.6660900115967 1999 12.5165004730225 2000 13.3213195800781 2001 14.2099304199219 2002 15.3504104614258 2003 16.4827098846436 2004 17.3991107940674 2005 18.249719619751 2006 19.3810195922852 2007 20.4003601074219 2008 21.5685501098633 2009 22.5155696868896 2010 23.8770503997803 2011 25.6037197113037 2012 26.8789100646973 2013 27.7383308410645 2014 30.4434604644775 2015 31.6328601837158 2016 32.2094306945801 2017 32.6133003234863 2018 33.0337181091309 2019 33.9015007019043 2020 34.9937705993652 2021 36.3748016357422 2022 37.2648582458496