condition mean min max ZT0-3 2.95 2.95 2.95 ZT4-7 9.0 9.0 9.0 ZT8-11 13.950000000000001 13.950000000000001 13.950000000000001 ZT12-15 2.85 2.85 2.85 ZT16-19 1.75 1.75 1.75 ZT20-23 4.2 4.2 4.2