Hard to say, my reason for guessing older is that the pile appears to be in a fairly dense woodland area. In these types of situations materials do not break down as quickly as they would in direct sunlight, the boogie board on the bottom right leads me to believe the pile has at least partial sun exposure (or it blew from somewhere else / another pile with more sun).

I have seen a 90’s USA football sit exactly like that in a pile for years (5+) and still look relatively inflated, although I bet if you pick that ball up you will quickly realize it has little air and is largely held together by the structure of the material.