<P> A Key Stage is a stage of the state education system in England, Wales, Northern Ireland and the British Territory of Gibraltar setting the educational knowledge expected of students at various ages . The term is also used in some other countries such as Hong Kong and Australia (some states) although the ages at which each Key Stage applies differ from England . </P> <P> The stages are as follows: </P> <Table> <Tr> <Th> Key Stage (KS) </Th> <Th> Ages </Th> <Th> Duration </Th> <Th> School years (Y) </Th> <Th> Final exams </Th> </Tr> <Tr> <Td> 0 </Td> <Td> 3--5 </Td> <Td> 2 years (1 compulsory) </Td> <Td> Nursery and Reception </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> 5 - 7 </Td> <Td> 2 years </Td> <Td> 1 - 2 </Td> <Td> KS1 SATS, Phonics and Reading Check (taken in Year 1 but may be retaken, if failed, in Year 2) </Td> </Tr> <Tr> <Td> </Td> <Td> 7 - 11 </Td> <Td> 4 years </Td> <Td> 3 - 6 </Td> <Td> SATS, eleven plus exam (generally only for Grammar school entry) </Td> </Tr> <Tr> <Td> </Td> <Td> 11 - 14 </Td> <Td> 3 years </Td> <Td> 7 - 9 </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> 14 - 16 </Td> <Td> 2 years </Td> <Td> 10 - 11 </Td> <Td> GCSEs </Td> </Tr> <Tr> <Td> </Td> <Td> 16 - 18 </Td> <Td> 2 years </Td> <Td> 12 - 13 </Td> <Td> A-Levels, AS - Levels, NVQs, National Diplomas, International Baccalaureate </Td> </Tr> </Table> <Tr> <Th> Key Stage (KS) </Th> <Th> Ages </Th> <Th> Duration </Th> <Th> School years (Y) </Th> <Th> Final exams </Th> </Tr>

What key stage is a 12 year old
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