I am pleased that he has saved her family the horror of a trial.
It looks as though it depends on when he pleaded guilty. If it was only today then that seems to be a 1/10 reduction on his sentence.
DETERMINING THE LEVEL OF REDUCTION
The maximum level of reduction in sentence for a guilty plea is one-third
D1. Plea indicated at the first stage of the proceedings
Where a guilty plea is indicated at the first stage of proceedings a reduction of
one-third should be made (subject to the exceptions in section F). The first stage will normally be the first hearing at which a plea or indication of plea is sought and recorded by the court.
D2. Plea indicated after the first stage of proceedings – maximum one quarter – sliding
scale of reduction thereafter
After the first stage of the proceedings the maximum level of reduction is
one-quarter (subject to the exceptions in section F).
The reduction should be decreased from one-quarter to a maximum of one-tenth on the first day of trial having regard to the time when the guilty plea is first indicated to the court relative to the progress of the case and the trial date (subject to the exceptions in section F).
The reduction should normally be decreased further, even to zero, if the guilty plea is entered during the course of the trial.
For the purposes of this guideline a trial will be deemed to have started when pre-recorded
cross-examination has begun
https://www.sentencingcouncil.org.u...or-Guilty-plea-Definitive-Guide_FINAL_WEB.pdf