condition mean min max ZT0-3 0.49027299999999996 0.49027299999999996 0.49027299999999996 ZT4-7 0.5303555 0.5303555 0.5303555 ZT8-11 0.663233 0.663233 0.663233 ZT12-15 0.4493115 0.4493115 0.4493115 ZT16-19 0.5435734999999999 0.5435734999999999 0.5435734999999999 ZT20-23 0.528649 0.528649 0.528649