condition mean min max ZT0-3 15.8973 15.8973 15.8973 ZT4-7 14.96525 14.96525 14.96525 ZT8-11 14.7315 14.7315 14.7315 ZT12-15 14.3905 14.3905 14.3905 ZT16-19 16.663899999999998 16.663899999999998 16.663899999999998 ZT20-23 13.5292 13.5292 13.5292