They are the chance results of sampling. If this objection were correct, then we would not find systematic, recurring patterns in the ranking of the provinces. Yet we find that the same few provinces appear at the top positions in all mathematics and science studies, and the same is true of the bottom positions. Ontario is never among the top achievers. This cannot be the effect of mere chance.
Somebody has to be average.
Such an attitude leads to complacency and is very dangerous. International studies show that the strongest performers are still not satisfied with their achievement, while the weak ones are complacent. This is one of the crucial causes of weak showing. Yet, the rough order of ranking of the provinces remained the same. This is not surprising.