Add 5.315m to data values 1958-1972 to refer to RLR<br>Add 6.204m to data values 1973-1993 to refer to RLR<br>Add 6.169m to data values for 1996 to refer to RLR<br>Add 6.134m to data values for 1998 to refer to RLR<br>Add 6.014m to data values 2008 onwards to refer to RLR<br>RLR is 9.463m below primary benchmark LUD 1