Duty Roulette Exp Reward Question

I'm currently leveling my monk and was just wondering how the exp reward for your daily low level dungeon roulette is calculated.

A couple days ago, I ran my duty roulette on my 31 monk and was sent to tam tara. After the dungeon, I got 100k exp rewarded to me for using the roulette.
Earlier today, I did my daily roulette and was sent to Haukke Manor, I only got 61k.

So I am kind of baffled right now with how the exp reward is calculated. Does it give me more exp if I get into a dungeon a few levels below me? Does it give me less exp when i do a dungeon closer to my level?

It's based on the discrepancy between your current level and the level it syncs you down to. So you'll get more XP for lower dungeons. On the flipside, you get more XP per mob in higher dungeons. So it's a bit of a trade off.