condition mean min max ZT0-3 7.95 7.95 7.95 ZT4-7 2.4 2.4 2.4 ZT8-11 8.05 8.05 8.05 ZT12-15 18.2 18.2 18.2 ZT16-19 12.35 12.35 12.35 ZT20-23 23.45 23.45 23.45