condition mean min max ZT0-3 23.363446 23.363446 23.363446 ZT4-7 25.536644 25.536644 25.536644 ZT8-11 23.7564555 23.7564555 23.7564555 ZT12-15 23.843346 23.843346 23.843346 ZT16-19 21.681304500000003 21.681304500000003 21.681304500000003 ZT20-23 23.584558 23.584558 23.584558