In the 35 years of the Booker there were five years that less than six books were on the short list and two years (1980 and 1981) when there were seven on the short list.
There is a long list, but that has only started to be released the year before last. In 2003 there were 23 books on the long list, last year there wer 20 and the year before that there were 24. Publishers can submit books and judges can call for books to be submitted. Last year 110 were submitted and another 10 were called.
Over the 35 years there were a total of 201 novels on the short lists from 134 authors.
Of the 97 nominated once, there were 13 winners and 3 co-winners.
Of the 19 nominated twice, there were 7 winners and one two-time winner (J. M. Coetzee).
Of the 10 nominated thrice there were four winners, 1 co-winner and 1 two-time winner (Peter Carey).
Of the 5 four time nominees, all but William Trevor have won once. The other four time nominees are Ian McEwan, Salmon Rushdie, Thomas Keneally and Penelope Fitzgerald.
The 2 five time nominees are Margaret Atwood (first nominated in 1986 and won in 2000) and Beryl Bainbridge (nominated twice in the 70s and three times in the 90s, but never won).
There was 1 six time nominee: Iris Murdoch who won on her fourth nomination in 1978 and was nominated twice more in the 1980s.
See: List of winners and shortlisted authors of the Booker Prize for Fiction, Institutional purge in the publishing industry