I want to know the answer to the following question:
When did the abbreviation CDMX begin to take hold?
All the background I'm provided with is that "This motto was quickly adopted as a city nickname, but has faded since the new motto Capital en Movimiento ("Capital in Movement") was adopted by the administration headed by Marcelo Ebrard, though the latter is not treated as often as a nickname in media.". Is that enough to answer the question?
Answer: no