What is a good age bracket for this pile of trash I found on my land?

https://lemmy.world/post/44743107

I think I found the cassette player, although it dates it to the 80s… Although it could of been an old object dumped alongside more contemporary ones, as the cassette doesn’t appear to be as aged as other objects…

https://www.ebay.com/itm/405015397001

That ball is way too inflated, it has not been sitting in the sun for over a decade.
The seams are ripped and decaying and there’s moss or lichen growing on it. I wouldn’t doubt for a moment that that ball has been in the woods for 15 or 20 years. It’s not just going to flatten like a balloon when it’s not at full pressure anymore.