Thanks for your replies. Fully understand that it's a random selection and I am aware of this. My question was more: Based on your experience of your flights to Canada, how many % of the arriving passengers were tested...
For example, when I entered Usbekistan in May, the rules also stated that there could be random tests at the airport. In fact however: EVERYONE got tested once I arrived there. Then Ecuador last December: All arriving passengers needed to go into a room where the PCR-Certificates were checked and approx. every 10th person (randomly selected) needed to additionally do an on-arrival test in a seperate room.
I know it is not possible to give exact numbers, but just a broad estimation would be helpful (and how the process works...). So if you are saying that it depends on the origin of your flight: Are the guys who pick you for the tests waiting directly at the gate so that they know from where you were heading in?