Observance of the Passover - Timeline

I wonder what the precise timeline of the observance of the Passover would look alike. The following chart shows a basic interpretation I have put together as a starting point. I would like to hear your qualified feedback / additions / corrections. Had the Passover consistently been observed during the Intertestamental period? When after 70 AD did the Jews / Christians start again to observe the Passover (in limited form without the temple)?