Add 3.653m to data values 1967-1977 to refer to RLR<br>Add 7.047m to data values for 1977 to refer to RLR<br>Add 3.653m to data values 1977-1978 to refer to RLR<br>Add 7.047m to data values for 1978 to refer to RLR<br>Add 3.653m to data values 1978-1979 to refer to RLR<br>Add 7.047m to data values for 1979 to refer to RLR<br>Add 3.653m to data values 1979 onwards to refer to RLR<br>RLR is 11.166m below primary benchmark SJOE4-1979