condition mean min max ZT0-3 0.39213000000000003 0.1565765 0.602095 ZT4-7 0.145716 0.145716 0.145716 ZT8-11 0.6736305 0.6736305 0.6736305 ZT12-15 1.7659097499999998 1.1935894999999999 2.33823 ZT16-19 3.37835 3.37835 3.37835 ZT20-23 0.9231845 0.9231845 0.9231845