<Tr> <Th> Devolution </Th> <Td> 31 July 1998 </Td> </Tr> <Tr> <Th_colspan="2"> Area </Th> </Tr> <Tr> <Th> Total </Th> <Td> 20,779 km (8,023 sq mi) </Td> </Tr> <Tr> <Th_colspan="2"> Population </Th> </Tr>

What is the area of wales in square miles