condition mean min max ZT0-3 12.5 12.5 12.5 ZT4-7 31.7 31.7 31.7 ZT8-11 6.15 6.15 6.15 ZT12-15 27.3 27.3 27.3 ZT16-19 58.95 58.95 58.95 ZT20-23 19.35 19.35 19.35