condition mean min max ZT0-3 22.85 22.85 22.85 ZT4-7 4.2 4.2 4.2 ZT8-11 15.2 15.2 15.2 ZT12-15 23.95 23.95 23.95 ZT16-19 19.2 19.2 19.2 ZT20-23 6.3 6.3 6.3