condition mean min max ZT0-3 3.255165 3.255165 3.255165 ZT4-7 1.705965 1.705965 1.705965 ZT8-11 2.26857 2.26857 2.26857 ZT12-15 3.24476 3.24476 3.24476 ZT16-19 4.341575000000001 4.341575000000001 4.341575000000001 ZT20-23 2.94199 2.94199 2.94199