A Freedom of Information request asked Ofcom how many cases of interference to radio amateurs had been investigated by Ofcom and successfully concluded with elimination of the interference – Ofcom admitted they did not know
It appears if Ofcom simply go through what they deem as the appropriate procedure during the interference investigation they will mark the case as either ‘resolved’ or ‘cleared’ irrespective of whether the interference has been eliminated.
The Ofcom FoI reply says:
“Please be advised that ‘resolved’ or ‘cleared’ for our purposes means that we have completed all actions that we can. This may not remove the interference as the interference source may be unidentifiable, identified but physically inaccessible or identified and in a location that the owner of the site may not permit entry to, and it may be deemed disproportionate to seek a warrant to force entry.”
Read the FoI reply which contains the number of cases Ofcom investigated in 2017-18 and 2018-19
https://www.ofcom.org.uk/__data/assets/pdf_file/0025/182284/investigations-into-radio-amateurs-foi.pdf
Ofcom Published responses to FOI requests page
https://www.ofcom.org.uk/about-ofcom/foi-dp/foi-responses