condition mean min max ZT0-3 3.5728299999999997 3.5728299999999997 3.5728299999999997 ZT4-7 2.648335 2.648335 2.648335 ZT8-11 2.71715 2.71715 2.71715 ZT12-15 4.16159 4.16159 4.16159 ZT16-19 4.15278 4.15278 4.15278 ZT20-23 4.4217949999999995 4.4217949999999995 4.4217949999999995