Add 5.588m to data values 1954-1965 to refer to RLR<br>Add 5.604m to data values 1966-1971 to refer to RLR<br>Add 5.608m to data values 1972-1975 to refer to RLR<br>Add 5.612m to data values 1976-1981 to refer to RLR<br>Add 5.619m to data values 1982-1991 to refer to RLR<br>Add 5.626m to data values 1992 onwards to refer to RLR<br>RLR is 9.873m below primary benchmark BM Yokosuka (i)