Instead of just filtering by range in Tops, can you filter random values within a range using an expression?

"Please look at image attached"

i.e I have 495 Wedge Index's generated.

I would like to randomly delete 200 index's at random and not in a sequential order that is set in the range. So a total of 200 index's will be deleted but selected at random.

Would this be done in using a filter by range or filter by expression.

If so. what expression is best to do this.