Post-op MRI

Hello to everyone ! I hope you're feeling as best as you could!

I was wondering does anyone know what's the distance between the place where the cerebral tonsils should be and the first vertebra - C1. Because in the last MRI reading (6 months after the decompression) it's written that the herniatnion of the tonsils is down to the C1. I was just wondering and I couldn't find such info nowhere. Thanks in advance and i wish you all the best !

Its a very small herniation and dependent on posture about 4 mm give or take.