Add 5.491m to data values 1958-1971 to refer to RLR<br>Add 5.983m to data values 1973-1977 to refer to RLR<br>Add 5.844m to data values 1980-1996 to refer to RLR<br>Add 5.581m to data values 1998-2002 to refer to RLR<br>Add 5.811m to data values 2003 onwards to refer to RLR<br>RLR is 10.646m below primary benchmark HO 2