condition mean min max ZT0-3 21.55 21.55 21.55 ZT4-7 3.0 3.0 3.0 ZT8-11 20.9 20.9 20.9 ZT12-15 19.6 19.6 19.6 ZT16-19 32.6 32.6 32.6 ZT20-23 20.95 20.95 20.95