10. The method of claim 2 , wherein ranking the plurality of results comprises, for each group: calculating a quality indicator for the group from a number of group parameters including a sum of relevance scores of the document portions in the group, the number of the one or more search terms per document portions in said group and the average number of associated numerical values per document portion in said group.
2. The method of claim 1 , wherein: each results group comprises the document portions corresponding to the numerical values enclosed by its interval; and the step of ranking the results groups comprises, for each results group, calculating a ranking score from the document portions comprised in the results group.