condition mean min max ZT0-3 5.4 5.4 5.4 ZT4-7 4.9 4.9 4.9 ZT8-11 3.85 3.85 3.85 ZT12-15 8.75 8.75 8.75 ZT16-19 5.699999999999999 5.699999999999999 5.699999999999999 ZT20-23 6.85 6.85 6.85