An extract from yesterday's Hansard.
John Mann: To ask the Leader of the House how many current hon. Members have redesignated their main home for the purposes of the additional costs allowance on three or more occasions. 
Chris Bryant: It is not possible to provide this information without going through each individual Member's paper records as the information as requested is not held electronically and nomination forms, indicating where a main and second home are located, were only required from 2003 onwards.
The answer could therefore be provided only at disproportionate cost.
Personally, I would have just called the Daily Telegraph. They have it all on CD.