Gravity's Rainbow
Notes
- No data available for before 1980, 1982–1985, 1987–1989, 1996.
- Data is incomplete for 1980, 1981, 1986, 1990, 1991, 1994 and 1997.
- Specific dates (rather than just a year) only recorded in the 1980s and since 2005.
- Reading of periodicals only recorded since 2005.