Year % gross 1970 13.3099298477173 1971 13.4134197235107 1972 13.7724103927612 1973 14.0854597091675 1974 14.2776002883911 1975 14.7816696166992 1976 15.2671804428101 1977 15.751540184021 1978 16.5342807769775 1979 17.4059391021729 1980 18.537769317627 1981 19.7116603851318 1982 21.0575695037842 1983 22.3192195892334 1984 23.4860095977783 1985 24.0462303161621 1986 23.7194499969482 1987 23.7245101928711 1988 23.4989204406738 1989 22.760139465332 1990 22.9744491577148 1991 23.2047805786133 1992 23.0252799987793 1993 23.130729675293 1994 23.4071006774902 1995 23.9148006439209 1996 24.1278495788574 1997 24.1755294799805 1998 24.7201309204102 1999 24.9929504394531 2000 25.5493793487549 2001 26.8518009185791 2002 27.84255027771 2003 28.951509475708 2004 30.4780807495117 2005 31.3897304534912 2006 32.4221000671387 2007 33.3528709411621 2008 35.2937202453613 2009 37.0730590820312 2010 38.9914588928223 2011 40.1870498657227 2012 41.4295616149902 2013 44.0412483215332 2014 42.8448791503906 2015 43.3706283569336 2016 42.8496589660645 2017 43.0901489257812 2018 43.2764015197754 2019 43.8056602478027 2020 44.3791809082031 2021 44.7816696166992 2022 44.6213912963867