condition mean min max ZT0-3 4.6 4.6 4.6 ZT4-7 1.6 1.6 1.6 ZT8-11 28.5 28.5 28.5 ZT12-15 36.25 36.25 36.25 ZT16-19 6.25 6.25 6.25 ZT20-23 15.05 15.05 15.05