condition mean min max ZT0-3 5.15 5.15 5.15 ZT4-7 6.5 6.5 6.5 ZT8-11 1.6 1.6 1.6 ZT12-15 10.75 10.75 10.75 ZT16-19 23.6 23.6 23.6 ZT20-23 29.65 29.65 29.65