condition mean min max ZT0-3 18.323050000000002 18.323050000000002 18.323050000000002 ZT4-7 15.882200000000001 15.882200000000001 15.882200000000001 ZT8-11 22.27915 22.27915 22.27915 ZT12-15 19.67535 19.67535 19.67535 ZT16-19 18.619 18.619 18.619 ZT20-23 19.3453 19.3453 19.3453