condition mean min max ZT0-3 20.4 20.4 20.4 ZT4-7 3.9 3.9 3.9 ZT8-11 8.7 8.7 8.7 ZT12-15 4.45 4.45 4.45 ZT16-19 16.65 16.65 16.65 ZT20-23 3.55 3.55 3.55