condition mean min max ZT0-3 4.10028 4.10028 4.10028 ZT4-7 2.7179349999999998 2.7179349999999998 2.7179349999999998 ZT8-11 3.3999699999999997 3.3999699999999997 3.3999699999999997 ZT12-15 4.25859 4.25859 4.25859 ZT16-19 5.858829999999999 5.858829999999999 5.858829999999999 ZT20-23 5.057595 5.057595 5.057595