Plotted entries from OPSLOG files in VIMOS report BIASRMS, plot 6, data set parQ4lo:

DATE       MJD-OBS      parameter values
==========================================================================
2008-11-19 54789.591453 1.21813414573956	parQ4lo
2008-11-20 54790.548764 1.20937777511879	parQ4lo
2008-11-21 54791.516456 1.21934599842889	parQ4lo