condition mean min max ZT0-3 35.92855 32.206849999999996 39.65025 ZT4-7 19.8955 19.8955 19.8955 ZT8-11 19.614 19.614 19.614 ZT12-15 0 0 0 ZT16-19 22.54465 22.54465 22.54465 ZT20-23 21.855 21.855 21.855