Why are SQL search results grouped in sets of only five items ?

The search results page is divided into two sections – list items and document items.
This is to avoid a situation in which only documents are selected by a search (because of the number
of times the search word appears in a document).
Because there are thus potentially a number of list items AND a number of document items selected
it was decided that the most suitable number of list items and documents per page would be five
(each) – i.e a possible total of ten.