I've never worked on two projects with the same team. There's as much learning about how to work with new, particular individuals as there is to learn about what the client needs.

Insomuch that anything has remained constant, it was pretty much just the underlying programming language, but even that has changed dramatically over the years, as well as opinions on the best way in which one should write it. Certainly my understanding of it has drastically improved.

And I'm not exactly sure what you're suggesting by "raw data". What sort of data? Collected and stored how? Reported on in what ways?