Diamond RNG

I recently came back to the game after many years and finally reached the point where I could comfortably farm endgame content. Over the past couple weeks I had mainly been farming coal for a bit of trading but mostly spawning diamonds. So far I am up to 5 diamonds and every single one so far has been a 'no cap', I was wondering if this is expected or if I am just getting unlucky. If anyone has any statistics or data about the expected/average stats of a diamond pet that would be greatly appreciated.

40% of diamonds on average can cap in tower damage, you're unlucky for sure but it's not that uncommon to be that far behind average either.

That's good to know, thanks for the info. Hopefully I can get at least 1 capping diamond in the next 5.