Year % gross 1971 0.205970004200935 1972 0.268810003995895 1973 0.277579993009567 1974 0.264450013637543 1975 0.224319994449615 1978 0.207120001316071 1979 0.213170006871223 1981 0.189820006489754 1982 0.222420006990433 1983 0.22503000497818 1984 0.237139999866486 1985 3.18009996414185 1986 4.50614023208618 1987 3.9543399810791 1988 3.88632988929749 1989 3.97365999221802 1990 4.20310020446777 1991 4.51412010192871 1992 5.02715015411377 1993 5.19844007492065 1994 5.52661991119385 1995 5.75713014602661 1997 6.83936977386475 1998 7.15124988555908 1999 6.80279016494751 2000 6.52913999557495 2001 6.68273019790649 2002 7.38290977478027 2003 8.0675802230835 2004 8.94169044494629 2005 10.860969543457 2006 13.7868299484253 2007 16.1882495880127 2008 17.9324493408203 2009 20.8057994842529 2010 25.4554100036621 2011 28.9796199798584 2012 30.2375202178955 2013 27.6796493530273 2014 26.974100112915 2015 29.1438007354736 2016 30.173210144043 2017 32.7392692565918 2018 36.6724281311035 2019 37.9658088684082 2020 39.7459297180176