condition mean min max ZT0-3 6.5681666666666665 5.480995 7.607184999999999 ZT4-7 5.138235 5.138235 5.138235 ZT8-11 6.69773 6.69773 6.69773 ZT12-15 6.386795 5.899595 6.873995000000001 ZT16-19 6.378299999999999 6.378299999999999 6.378299999999999 ZT20-23 8.49242 8.49242 8.49242