Why do the texts rotate so frequently?

Each set text remains on the syllabus for three years, during which time two questions are set for each question paper. One of these is an extract question. We offer three series per year, with three different time zones requiring separate papers in June and November, with one in March. This amounts to 14 questions per year over three years: in addition to contingency papers, this amounts to 48 separate questions on each text. To retain a text beyond this time would significantly compromise the quality of the assessment as it would be impossible to avoid duplication of text for extracts and question foci, except in very long texts which are only occasionally offered at IGCSE level.