Question about jungle catch up xp?

Does any junglers out there know how high jungle catch up xp is, and how it fully works. I was playing a game of olaf one day against a trundle jungle, and I was sitting about 2 levels up on him, and about 30 to 40 cs at a time. However this trundle at lime lvl 9 just caught up significantly in levels and stayed even with me. Is the catch up xp a bit too high?