It's not a matter of "percentage" but rather a vast majority of earthquakes occur at plate boundaries.

Here's a breakdown:

* 90% of earthquakes occur along convergent plate boundaries, where plates collide.

* Another significant percentage occur at divergent plate boundaries, where plates pull apart.

* Only a very small percentage of earthquakes happen within plate interiors, often associated with faults reactivated by stresses from plate movement.

So, while it's difficult to give an exact percentage, it's safe to say that over 90% of earthquakes happen at plate boundaries.