condition mean min max ZT0-3 278.461134 278.461134 278.461134 ZT4-7 261.51415599999996 261.51415599999996 261.51415599999996 ZT8-11 217.26982049999998 217.26982049999998 217.26982049999998 ZT12-15 203.507609 203.507609 203.507609 ZT16-19 223.275657 223.275657 223.275657 ZT20-23 247.6053705 247.6053705 247.6053705