Randomizing a group of prims with the same attribute

Hi all, I want to randomize an attribute on a set of prims such that each frame it randomizes to the same value for all of them. I can currently do the randomization each frame but no matter how I set up the rep.distribution, it re-samples for every prim which I do not want. Setting the num_samples to 1 does not help this either. If anyone has a solution please let me know.