Whats the percentage of increase drop rate for all treasure hunter levels?
does it increase by 50% for level 1 and 100% for level 2 for example?
or does it have a lottery system like a slot machine where if you fail to get the drop, it'll roll again per treasure hunter level at a lower rate for each treasure hunter level beyond that point?
e.g 50% increase from drop rate for level 1 (E.g 20% drop rate increased by 50% making it a 30% drop rate instead), next roll is 40% increase from the original drop rate for level 2, next roll 35% increase from the original drop rate for level 3, next roll 30% increase from the original drop rate for level 4? (These numbers are random numbers i chose for this example and don't reflect any solid data from other's testing)

or perhaps the system for treasure hunter is something completely different?
please give some information or hints on this matter