<Table> One pound <Tr> <Td_colspan="2"> United Kingdom </Td> </Tr> <Tr> <Th> Value </Th> <Td> 1 pound sterling </Td> </Tr> <Tr> <Th> Mass </Th> <Td> 8.75 g </Td> </Tr> <Tr> <Th> Diameter </Th> <Td> 23.03 - 23.43 mm </Td> </Tr> <Tr> <Th> Thickness </Th> <Td> 2.8 mm </Td> </Tr> <Tr> <Th> Edge </Th> <Td> Alternately milled and plain </Td> </Tr> <Tr> <Th> Composition </Th> <Td> (Outer ring) Nickel - brass (76% Cu, 20% Zn, and 4% Ni) (Inner planchet) Nickel - plated alloy </Td> </Tr> <Tr> <Th_colspan="2"> Obverse </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Design </Th> <Td> Queen Elizabeth II </Td> </Tr> <Tr> <Th> Designer </Th> <Td> Jody Clark </Td> </Tr> <Tr> <Th> Design date </Th> <Td> 2016 </Td> </Tr> <Tr> <Th_colspan="2"> Reverse </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Design </Th> <Td> Rose, leek, thistle, and shamrock encircled by a coronet </Td> </Tr> <Tr> <Th> Designer </Th> <Td> David Pearce </Td> </Tr> <Tr> <Th> Design date </Th> <Td> 2016 </Td> </Tr> </Table> <Tr> <Td_colspan="2"> United Kingdom </Td> </Tr>

When was the new £1 coin introduced