condition mean min max ZT0-3 4.2 4.2 4.2 ZT4-7 3.3 3.3 3.3 ZT8-11 5.699999999999999 5.699999999999999 5.699999999999999 ZT12-15 19.05 19.05 19.05 ZT16-19 2.2 2.2 2.2 ZT20-23 25.5 25.5 25.5