Do you work for Prevent? They seems to think ones who have carried out 94% of terrorist attacks are less of a concern than the other 6%.
“Of the 8,778 referrals to Prevent, just 870 were for “Islamic extremism”, compared with 1,798 linked to “extreme Right-wing” ideology and a mere 21 connected to “Left-wing extremism”.
If a submission is made through the Prevent Programme the submitting organisation is required to state a Type of Concern from a predefined list of categories. That is where the data you quote comes from; it's not generated by the Prevent Programme itself. Over half of referrals are tagged No Identified Ideology.