Well more than 2% probably closer to 10% overall. But that isn't the way to measure it I don't think. I use it 95% of the time I am planning to use a tripod - that sounds obvious but I plan whole efforts/trips expecting to use a tripod for the types of shots I am taking. Sometimes I don't bother if the shutter speeds are up.

There are trips/efforts that I know I am not going to use it and typically don't. When I don't have specific plan and I take one along, it is very much an element of the time I have available to take either the pix, or ground that I have to cover.

If I am going to the local botanical garden then 80%+, If I am covering a new area and can return, then I usually bring it but don't use it often as I will return w/ a plan.

The thing that I found is that when I do want to use it, having to fiddle w/ the less capable models is really frustrating - go with quality.