condition mean min max ZT0-3 3.35 3.35 3.35 ZT4-7 31.5 31.5 31.5 ZT8-11 18.65 18.65 18.65 ZT12-15 17.35 17.35 17.35 ZT16-19 10.8 10.8 10.8 ZT20-23 8.9 8.9 8.9