condition mean min max ZT0-3 11.95 11.95 11.95 ZT4-7 13.5 13.5 13.5 ZT8-11 12.35 12.35 12.35 ZT12-15 30.35 30.35 30.35 ZT16-19 19.7 19.7 19.7 ZT20-23 13.05 13.05 13.05