condition mean min max ZT0-3 11.9 11.9 11.9 ZT4-7 29.2 29.2 29.2 ZT8-11 39.05 39.05 39.05 ZT12-15 25.95 25.95 25.95 ZT16-19 18.3 18.3 18.3 ZT20-23 2.55 2.55 2.55