condition mean min max ZT0-3 8.175347 8.175347 8.175347 ZT4-7 8.388143 8.388143 8.388143 ZT8-11 8.162859000000001 8.162859000000001 8.162859000000001 ZT12-15 8.432577 8.432577 8.432577 ZT16-19 8.175347 8.175347 8.175347 ZT20-23 7.731084 7.731084 7.731084