Instance variables/internal state for Blueprint Function Nodes

Is there a way for a Blueprint Node (declared using UFUNCTION) to hold internal state, or instance variables?

I would like to compute a running average, which requires the function to keep a history of previously computed averages.

Example:

new TArray → RunningAverageNode (holding array of last N averages) → Average of last N Averages.

Is there any way to do this? I am exposing the UFUNCTION/Blueprint Node through an Actor Component.