[arcticfox]

Exactly, your first sentence isn't saying anything at all about the next 5730. Without outside knowledge of exponential decay, there's zero reason to imply anything about the next 5730.

If you instead say "the half-life of Carbon 14 is 5730 years" then you would be saying something about the next 5730 as well.

The English of "8 out of 10 businesses fail in their first year." is completely unambiguous.