Awaiting after Second CO Contact

Hi, I lodged my application on Oct 2016 and CO contacted for medicals and PCC on 1st Nov 2016. Further to it CO on 8th Dec 2017 asked to amend my PCC as per the full name in passport, which was obtained and replied on 15th Dec 2016. How long will be the wait for a grant ? Please suggest
it could take 4-12 weeks from last CO Contact