condition mean min max ZT0-3 8.1 8.1 8.1 ZT4-7 0.6 0.6 0.6 ZT8-11 16.95 16.95 16.95 ZT12-15 19.049999999999997 19.049999999999997 19.049999999999997 ZT16-19 7.55 7.55 7.55 ZT20-23 17.4 17.4 17.4