All 4 non-stop flights YXE-YYZ on 18 Apr are M9, if any were in doubt I'd say the 1010 departure appears more heavily booked but it's still M9 actually all the way down to V9.
As for the way back, YYZ-YXE on 21 Apr, again all 4 flights are M9, with the middle two being slightly more booked than the early morning or late night.
Hope this helps.
QQ