At what age should children start following Cambridge Primary curriculum frameworks?

Cambridge Primary is organised into six stages, each of which represents a year of primary education. Stage 1 is the first year of primary school, when children are approximately 5 years old, and stage 6 is the final year, during which children reach their 11th birthday. The curriculum frameworks provide learning objectives for each of these stages. However, in some educational contexts it may be appropriate to introduce the stages at slightly different ages or to expand/contract some stages so that they take more/less than a year to complete.