Well, Esperanto is only a little over a century old, and (as far as I know) there are no native speakers. It is a written language. That has probably slowed down its rate of change. I do know that the suffix for forming country names has been deprecated. So, Russia and Germany today are Germanio and Rusio instead of Germanujo (country of German speakers) and Rusujo.

Ceci n'est pas un seing.