condition mean min max ZT0-3 29.25 29.25 29.25 ZT4-7 3.5 3.5 3.5 ZT8-11 4.699999999999999 4.699999999999999 4.699999999999999 ZT12-15 5.5 5.5 5.5 ZT16-19 24.85 24.85 24.85 ZT20-23 7.699999999999999 7.699999999999999 7.699999999999999