condition mean min max ZT0-3 6.55 6.55 6.55 ZT4-7 6.5 6.5 6.5 ZT8-11 16.9 16.9 16.9 ZT12-15 2.75 2.75 2.75 ZT16-19 20.95 20.95 20.95 ZT20-23 10.2 10.2 10.2