I think it's a lot harder than it sounds. First, nobody can estimate time well enough to know how long something would have taken without AI. And then, it's comparing apples to oranges - there's the set of things people did using an AI agent, and the set of things they would have done if they hadn't used AI, and the two are just not directly comparable. The AI agent set would definitely have more lines of code, that's all I could really say. Maybe it would also contain a larger maintenance burden, lower useful knowledge in humans, projects that didn't need to be done or could have been done in a smarter way, etc.