condition mean min max ZT0-3 13.5 13.5 13.5 ZT4-7 4.1 4.1 4.1 ZT8-11 8.4 8.4 8.4 ZT12-15 9.299999999999999 9.299999999999999 9.299999999999999 ZT16-19 1.85 1.85 1.85 ZT20-23 1.9 1.9 1.9