A lovely and clever way to visualize this data. Some numbers surprised me, like why did France require so many nuclear tests -- some well into the 1990s -- given their rather small warhead inventory? Perhaps they were simply posturing, to feel more important on the world stage.
Also, I didn't realize the Soviets had tested nukes all over their territory, with such a multitude of sites. Just one regret: atmospheric and underground tests were not differentiated.
Overall, 14 minutes well spent! Thank you for posting this link.