condition mean min max ZT0-3 3.918525 3.918525 3.918525 ZT4-7 2.71856 2.71856 2.71856 ZT8-11 3.5829750000000002 3.5829750000000002 3.5829750000000002 ZT12-15 5.558225 5.558225 5.558225 ZT16-19 5.473865 5.473865 5.473865 ZT20-23 3.212135 3.212135 3.212135