condition mean min max ZT0-3 19.86545 19.296599999999998 20.4343 ZT4-7 18.7006 18.7006 18.7006 ZT8-11 35.063900000000004 35.063900000000004 35.063900000000004 ZT12-15 0 0 0 ZT16-19 29.196550000000002 29.196550000000002 29.196550000000002 ZT20-23 23.24455 23.24455 23.24455