condition mean min max ZT0-3 5.65 5.65 5.65 ZT4-7 2.7 2.7 2.7 ZT8-11 7.55 7.55 7.55 ZT12-15 10.75 10.75 10.75 ZT16-19 7.25 7.25 7.25 ZT20-23 32.75 32.75 32.75