Clarification: IRCC processing time information is NO longer based on how long it took to process 80% of applications.
IRCC information about processing times is vague and deliberately does NOT forecast how long it will take pending or future applications.
In particular, the IRCC online information describes its processing time for grant citizenship applications this way:
"This processing time tells you how long it took us to process most complete applications, in the past."
Most merely means at least one more than HALF. It is essentially the median timeline.
Current anecdotal reporting is consistent with this, many here still reporting their application still pending longer than a year.
Reminder: there is no statutory or regulatory time requirement for processing citizenship applications. Not even a "reasonable time" requirement.
Mandamus was a very long shot even back when grant citizenship processing dragged on past three years, largely because the length of time is NOT a ground for Mandamus. If there is no time requirement in which the Minister must act on a citizenship application, there cannot be a clear duty to make a decision within any particular length of time.
The length of time is a relevant factor if there are other facts and circumstances to show that the Minister has failed to take an action the Minister has a clear duty to take. These are difficult cases to win.
For a time, preliminary steps to pursue Mandamus, done by a competent lawyer, tended to help SOME (just some) applicants push CIC (back when there was a Conservative government) to proceed with processing the application, but again that was back when grant citizenship processing was dragging on for three and more years. And it was NOT cheap. (Similar efforts by applicants acting on their own behalf tended to be ignored by CIC.)