condition mean min max ZT0-3 2.4949380000000003 0.5723210000000001 4.417555 ZT4-7 2.372445 2.372445 2.372445 ZT8-11 0.738749 0.738749 0.738749 ZT12-15 0 0 0 ZT16-19 3.61709 3.61709 3.61709 ZT20-23 5.007795 5.007795 5.007795