condition mean min max ZT0-3 23.817999999999998 23.817999999999998 23.817999999999998 ZT4-7 20.400599999999997 20.400599999999997 20.400599999999997 ZT8-11 20.585 20.585 20.585 ZT12-15 21.457700000000003 21.457700000000003 21.457700000000003 ZT16-19 19.703000000000003 19.703000000000003 19.703000000000003 ZT20-23 21.90605 21.90605 21.90605