I'm afraid I'm unable to answer that question. I don't wish to be unhelpful, but the detail around armed forces compensation payment is very much a Ministry of Defence issue and they would have consulted at that time, so I'm not in a position to comment on the reasons behind the increase. I would suggest one of the reasons why they looked at it again would have been the increased operations internationally through the Gulf War, Iraq, Afghanistan, etc.
Evidence of meeting #74 for Veterans Affairs in the 41st Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was teams.
A recording is available from Parliament.