This figure is seldom used.

If ternary rhythm represents 4% of all music, it is present in less than 10% of it.

This is strange, since it is a primary ternary figure.

Your chances of meeting it increase as the tempo decreases.

An anapaest is a literary term indicating some imbalance.
The end of a word or phrase being stronger that its beginning.

This figure is a musical anapaest, because its longest note is placed on the weakest position of the beat.

The historical lack of interest for it attests this reality.