Gunownership had declined:
It says so right here
Of course, it could be just that the respondents chose not to admit having a firearm when called.
I mean, I always answer "No" when asked.
Strangely, several times, my entire firearms collection has been lost in tragic canoe accidents. Last time while I was driving to the range. The entire canoe-full fell into the creek and were lost forever. Tragic, I tell you.
I can't really remember.
Short term memory loss and all that.