condition mean min max ZT0-3 2.95 2.95 2.95 ZT4-7 3.4 3.4 3.4 ZT8-11 2.0 2.0 2.0 ZT12-15 23.950000000000003 23.950000000000003 23.950000000000003 ZT16-19 4.0 4.0 4.0 ZT20-23 3.35 3.35 3.35