From my understanding (and this you can verify on IRCC website), the PR process countdown begins from the date they receive an express entry online application while for non-express entry (paper), the countdown starts from the time the application is received at their offices, which is the AR. So if paper based applications take between 15 to 19 months (and now with Covid, IRCC says it could take up to 21 months), lets hope with the vaccine and with IRCCs goal to invite more immigrants starting this year, that there will be no delays and that they will be in a position to process applications between 15 and 19 months. To answer your question, you can estimate how long starting from your AR. It would also depend on your security background check and your medicals, from my understanding, the former can take long