condition mean min max ZT0-3 16.5 16.5 16.5 ZT4-7 4.8 4.8 4.8 ZT8-11 14.55 14.55 14.55 ZT12-15 3.0999999999999996 3.0999999999999996 3.0999999999999996 ZT16-19 24.75 24.75 24.75 ZT20-23 24.8 24.8 24.8