condition mean min max ZT0-3 2.5825449999999996 2.046515 3.118575 ZT4-7 5.2106449999999995 5.2106449999999995 5.2106449999999995 ZT8-11 3.4984450000000002 3.4984450000000002 3.4984450000000002 ZT12-15 0 0 0 ZT16-19 3.74477 3.74477 3.74477 ZT20-23 3.958915 3.958915 3.958915