condition mean min max ZT0-3 2.5565816666666668 1.74803 3.159725 ZT4-7 2.21748 2.21748 2.21748 ZT8-11 3.24518 3.24518 3.24518 ZT12-15 7.1372374999999995 6.550425 7.72405 ZT16-19 6.75583 6.75583 6.75583 ZT20-23 5.536300000000001 5.536300000000001 5.536300000000001