condition mean min max ZT0-3 4.6 4.6 4.6 ZT4-7 8.6 8.6 8.6 ZT8-11 12.2 12.2 12.2 ZT12-15 8.649999999999999 8.649999999999999 8.649999999999999 ZT16-19 4.95 4.95 4.95 ZT20-23 3.4 3.4 3.4