Among national companies, British Airways has sustained operations at Heathrow in London; in Frankfurt, it is Lufthansa; at the Roissy airport, it is Air France. These companies are very important.
I don't think there is a threshold. What we have to consider is the effect it has. We now know that Air Canada accounts for 50% of the activities at Montréal-Trudeau airport. That is a fact. What can we do about it? It is not the 50% that is problematic. British Airways accounts for a higher percentage of activities at Heathrow. What are the other conditions under which low-cost airlines can develop? That is the issue.
We have to address various factors, such as poor departure or arrival time slots, very high taxes, poor weather conditions, large distances to be served and a labour shortage.
These are the issues that become decisive. It is not necessarily the percentage of activities conducted by a national airline at a given airport. Moreover, those are issues that can be addressed, although Canada has not done so.
I don't know if we have to focus on a certain percentage. I also don't know whether my colleague Mr. Roy, who is an expert on operations, could say. In any case, I don't think such a percentage exists.