Information regarding prosecutions and convictions for blackmail offences from 2010 to 2018 can be found at the following link –
Filter the ‘Offence’ field to ’35 Blackmail’ to obtain these figures. The total number of defendants proceeded against as well as those convicted of blackmail for the 2008-2018 decade will appear in the pivot table.
However, specific information regarding blackmail offences, such as the offence of blackmail against people that demanded money to leave sites which they were occupying illegally, may be held on court record. But to be able to identify these cases, as they are not held centrally, we would have to access individual court records which would be of disproportionate cost.