If the judge decides that it's a 'Category 3' offence (i.e. where 'culpability' and 'harm' are both assessed as 'low) the 'starting point' sentence from which he has to work is 4 years imprisonment, with an actual sentence of between 3 and 5 years.
If only one of the two factors referred to above is assessed as 'high', it's a 'Category 2' offence and the starting point is 6 years (with an actual sentence of between 5 and 9 years).
If both factors are assessed as 'high', it's a 'Category 1'offence, with a starting point of 12 years (and an actual sentence between 9 and 16 years).
Those sentences refer to a first-time offender, who is convicted after a trial. An early guilty plea can see the sentences cut by a third. (A later guilty plea will see a lesser reduction). Previous convictions (especially for violence) can see sentencing pushed higher. (The maximum sentence is life imprisonment).
See pages 3 to 6 here:
http://sentencingcoun...ine_-_Crown_Court.pdf
(That's the actual document that judges MUST adhere to, unless there are very unusual circumstances).
Chris