Cheap flights to Germany

[tobeornottobe]

I'm planning to visit some of my family members in Germany. I was wondering when is the best time to visit in terms of cheap flights.

The flight would be between Toronto - Dusseldorf.

[Aristophanes]

The 3 cheapest times I flew to DUS were:

End of April
Mid of May
Day after Xmas

Air Canada started last May a direct route from YYZ - DUS. Super convenient.