The "official" table is available here:

A brief history of the codification

In the nineteenth century, the degree of distance and ascent was often deemed more important than the number of fells bagged

In 1906 [id31], Wakefield notes that the record is based on the most number of peaks over 2,000 feet which can be gained within 24 hours - "to exceed this time should not be encouraged"

From the 1960s, it became convention for Bob Graham's summits to be included in any 24 hour record

In 1971, the Bob Graham Club stipulated that a new record must at least include the summits gained by the previous record holder

In 1978, a minimum degree of prominence was set for any peaks; there must be at least a 50 foot drop in all directions

In 1989, the prominence threshold was increased to 250 feet and a minimum distance of 0.25 miles between any new peak was introduced

There has never been any rule on where a record must begin