I bet PD keep some guy locked in a room and whenever they need a baseline for times, they just say "New tests. Go fast." And come back in a few days to see how fast he's gone.
Haha but seriously I don't think anybody knows. Honestly I don't know if they really even have an actual person try to beat the gold times at the office; I don't even know how they determine the gold times. Or the silver, or bronze. And I really don't know why/how anybody outside of PD would have any idea how much they can beat the gold time by.