condition mean min max ZT0-3 28.2 28.2 28.2 ZT4-7 8.4 8.4 8.4 ZT8-11 7.35 7.35 7.35 ZT12-15 7.699999999999999 7.699999999999999 7.699999999999999 ZT16-19 4.25 4.25 4.25 ZT20-23 6.85 6.85 6.85