condition mean min max ZT0-3 33.6 33.6 33.6 ZT4-7 27.8 27.8 27.8 ZT8-11 9.8 9.8 9.8 ZT12-15 24.25 24.25 24.25 ZT16-19 19.05 19.05 19.05 ZT20-23 29.25 29.25 29.25