condition mean min max ZT0-3 6.2 6.2 6.2 ZT4-7 19.5 19.5 19.5 ZT8-11 14.25 14.25 14.25 ZT12-15 6.45 6.45 6.45 ZT16-19 28.55 28.55 28.55 ZT20-23 18.15 18.15 18.15