Add 5.878m to data values 1967-1972 to refer to RLR<br>Add 5.740m to data values 1979-1997 to refer to RLR<br>Add 5.634m to data values 1998-2002 to refer to RLR<br>Add 5.924m to data values 2003 onwards to refer to RLR<br>RLR is 11.200m below primary benchmark TG Pit