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?