I just want to clarify something regarding the PCC issue date. What u/subtain suggested above applies only to the country where you are currently residing. If you lived in another country 5 years ago, but haven't lived there since and have no plans to live there in the immediate future, a PCC issued by that country at point of time after you left, should be sufficient. You wouldn't need to get another clearance in future.
On the other hand, if you for example live in the United States while your application with CIC is pending, you will have to submit FBI clearance certificate issued within the last three months. That means you may have to get it more than once, depending upon your processing time at the Federal stage.