Previously, it was like this:
QUOTE
Cave 1: Levels 15 - 38
Split Caves 1 & 2: Levels 39 - 40
Cave 2: Levels 41 - 66
Split Caves 2 & 3: Levels 67 - 68
Cave 3: Levels 69 - 95
Split Caves 3 & 4: Levels 96 - 98
Cave 4: Levels 99 to 19.9k/9.9k
Split Caves 4 & 5: 10k/2.5k - 13.9k/6.9k
Cave 5: 14k/7k - 39.9k/29.9k
Split Caves 5 & 6: 32.5/18.9k - 65k/39.9k
Cave 6: 60k/30k - 119.9k/69,633k
Split Caves 6 & 7: 120k/60k - 195.5k/99.9k
Cave 7: 196k/100.5k - 415k/207.5k
Split Caves 7 & 8: 415k/207.5k - 499k/260k
Cave 8: 500k/261k - 900k/450k
Split Caves 8 & 9: 900k/450k - 1m/500k
Cave 9: 1 mil/500k - 2.3m/1.15m
Split Caves 9 & 10: 2.3m/1.15m - 2.5m/1.25m
Cave 10: 2.5 mil/1.25mil - infinite until Cave 11 comes out
Split Cave 7 is not 120k/60k anymore to enter.
Update: Dakowe got option to enter split Cave 7 at 170k/85k