<Tr> <Td> HW </Td> <Td> Bristol </Td> <Td> HX </Td> <Td> London (Central) (Middlesex before 1965) </Td> <Td> HY </Td> <Td> Bristol </Td> </Tr> <Tr> <Th> J </Th> <Td> J </Td> <Td> Durham </Td> <Td> JA </Td> <Td> Manchester (Stockport until 1974) </Td> <Td> JB </Td> <Td> Reading </Td> </Tr> <Tr> <Td> JC </Td> <Td> Bangor </Td> <Td> JD </Td> <Td> West Ham (Changed to London (Cent) from 1967 </Td> <Td> JE </Td> <Td> Peterborough (Cambridge until 1981) </Td> </Tr> <Tr> <Td> JF </Td> <Td> Leicester </Td> <Td> JG </Td> <Td> Maidstone (Canterbury until 1981) </Td> <Td> JH </Td> <Td> Reading (Hertfordshire until 1974) </Td> </Tr>

When did number plates change from black to yellow