What is the meaning of the number in the upper-right corner of the Watchtower screen?

And I would also add that the relationship between the number, the arrow on the dial, and the color makes little sense. Right now my arrow is straight up at "noon", rating is "fantastic" with a score of 1090. What's confusing to me is why my arrow is "only" pointing straight up at noon? Given there's NO scale range, the arrow location would imply to me that I have a long ways to go to be more secure. If I'm "fantastic" why isn't my arrow at say at 3 o'clock? Why can't the tool show a score range? How am I supposed to know what 1090 relates to? I find the watchtowner function in the lower half of the screen (need more 2FA, dupe passwords, etc.) fantastic. But the entire score/color/arrow location is utterly confusing and useless.