<Tr> <Td> 1961 </Td> <Td> 7,992,616 </Td> <Td> 7992616 </Td> </Tr> <Tr> <Td> 1971 </Td> <Td> 7,452,520 </Td> <Td> 7452520 </Td> </Tr> <Tr> <Td> 1981 </Td> <Td> 6,805,000 </Td> <Td> 6805000 </Td> </Tr> <Tr> <Td> 1991 </Td> <Td> 6,829,300 </Td> <Td> 6829300 </Td> </Tr>

Where is london and what is its significance