~Efflie used to be big 2~ish years ago but is now blank and has become a part of ~Danpo (the current petpage that reigns supreme)
Actively not encouraging or promoting another website (delete this if this is not allowed) but (you need an account to see links) is a guide from 2016. Can provide SS later if the link is not allowed
And (you need an account to see links) site shows past UC trades for 3+ years back so you can use that for reference
A note on BD pets - those BD stats listed on Danpo have remained relatively constantly and haven’t been truly updated in 3-4+ years
Did I save the best for last?? Absolutely. (you need an account to see links) . Although I don’t like the formatting personally, this petpage has information from all the way back to 2012. Enjoy it and hopefully you find what you’re looking for!! It doesn’t quite connect from 2012 all the way to present, but it should give you some insight!!