condition mean min max ZT0-3 14.299999999999999 14.299999999999999 14.299999999999999 ZT4-7 9.5 9.5 9.5 ZT8-11 3.85 3.85 3.85 ZT12-15 8.350000000000001 8.350000000000001 8.350000000000001 ZT16-19 3.95 3.95 3.95 ZT20-23 1.85 1.85 1.85