One of my network websites was upgraded. Which one?

I just received a payment on paypal, from someone who upgraded his website. The user had a different address on paypal from the one on the website.
So I can't find who that user is, and I don't know which website he upgraded. On the list with all the websites, you can see which ones are Pro Sites and which are not, but you you would have to go through all of them and try to identify which one was upgraded. When you have hundreds of websites this is a bit difficult, if not impossible. Is there a way I could identify which website was upgraded lately?

Thank you