condition mean min max ZT0-3 4.4 4.4 4.4 ZT4-7 5.8 5.8 5.8 ZT8-11 1.5 1.5 1.5 ZT12-15 12.5 12.5 12.5 ZT16-19 10.649999999999999 10.649999999999999 10.649999999999999 ZT20-23 10.25 10.25 10.25