There were many flights, based on our assessment, that used to cross Canadian airspace. It was between 80 to 140 flights a week. The majority of them did not land in Canada, but they typically flew through Canadian airspace on their way to other destinations. That is a significant number of flights that are now no longer able to cross.
Evidence of meeting #8 for Transport, Infrastructure and Communities in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was notam.
A recording is available from Parliament.