condition mean min max ZT0-3 19.5 19.5 19.5 ZT4-7 19.7 19.7 19.7 ZT8-11 2.0999999999999996 2.0999999999999996 2.0999999999999996 ZT12-15 23.55 23.55 23.55 ZT16-19 24.0 24.0 24.0 ZT20-23 30.75 30.75 30.75