condition mean min max ZT0-3 20.85 20.85 20.85 ZT4-7 2.1 2.1 2.1 ZT8-11 9.299999999999999 9.299999999999999 9.299999999999999 ZT12-15 13.35 13.35 13.35 ZT16-19 2.9000000000000004 2.9000000000000004 2.9000000000000004 ZT20-23 6.85 6.85 6.85