condition mean min max ZT0-3 3.8395224999999997 3.24167 4.437374999999999 ZT4-7 3.02895 3.02895 3.02895 ZT8-11 3.372065 3.372065 3.372065 ZT12-15 0 0 0 ZT16-19 4.15613 4.15613 4.15613 ZT20-23 4.12697 4.12697 4.12697