I think changes to phrases that don't change their meaning are interesting. Example: an ice cold beer and a nice cold beer mean pretty much the same thing.
I heard another one this morning on the radio in a story about coal. The phrase used is fluctuates widely, but I know I've also heard fluctuates wildly. Looking at the ngram, I'm surprised to see that "widely" is far more popular (although with 0 smoothing, it does fluctuate wildly ;-).
Any idea where either of these phrases comes from, which came first, and/or which is more correct? wildly makes more sense to me in most contexts, but widely makes sense too.