condition mean min max ZT0-3 635.462826 635.462826 635.462826 ZT4-7 516.3754105 516.3754105 516.3754105 ZT8-11 435.7243825 435.7243825 435.7243825 ZT12-15 488.6829545 488.6829545 488.6829545 ZT16-19 439.8016785 439.8016785 439.8016785 ZT20-23 489.24423249999995 489.24423249999995 489.24423249999995