Construction Queues

Hi, I don't know if this has been asked already and if it has, I am sorry. I was looking at the Construction Queues and noticed the Queue settings at the bottom right. I saw the option Emergency build. It says construction will move 2 times the normal speed and that when turned off, it will slow down to 50% normal speed. I don't know if the game is wrong or that I really need to go to bed (2am right now), but when I clicked on this option, the construction queue only went up to 150% and after a few turns, I turned it off, and it slowed down all the way to 25%. I thought "2 times" the normal rate would be 200% and slowed down to 50% would be, well, 50%.

Tell me I'm not going crazy.