Nuno P. "... converting to SQL or opening a new deal within the next 30 days, or something similar."
SQL and new deals are usually very different. Nevertheless, you are poking at what is called a time to won model. It is a curve showing the percent that are won (can be converted as well but far less useful) as a function of time since a starting event (opp creation, MQL conversion date, whatever...).
We have many blogs on how to do this. Here's one (with examples and a recipe).
https://www.funnelcast.com/post/win-rates-are-curves-not-numbers
Or you can use our free product.
Have fun with this. It's a very robust and powerful way to model demand generation and a sales pipeline.
DM me if you want help.