 And if you look at the really long arc here, it's amazing. I mean, go all the way back to the Babylonians, OK? Babylonians worked all day. You got the equivalent of 10 minutes, 10 minutes of light. 4,000 years later in the 19th century with kerosene lamps, things are better. A day's labor gets you five hours of light. And by the time Nordhaus does his light study in the 1990s, if you work a day, how much light do you get? Maybe 20,000 light.