Give it a What?

I found an idiom "Give it a shot" the other day. I learned it a long time ago, but I've completely forgotten it.

A couple of days later, I saw another a similar idiom "Give it a go", and I wondered what the difference was. I checked the dictionary but I couldn't find any specific difference.

I tried using Google Ngram which Tim kindly let me know. (Thank you, Tim!)

The result of a comparison;

 Hmm... Almost the same, but around 1985, it was inverted. But yet, no big difference.
 

By coincidence, just after I checked Google Ngram, I found an idiom "Give it a try."
So I tried checking Ngram again including "Give it a try."

Wow, "Give it a try" has been used overwhelmingly.
I somehow feel that "Give it a try" is subtly different from the other two.