condition mean min max ZT0-3 2.8892550000000004 2.8892550000000004 2.8892550000000004 ZT4-7 1.572825 1.572825 1.572825 ZT8-11 2.34602 2.34602 2.34602 ZT12-15 1.645382 1.645382 1.645382 ZT16-19 3.896105 3.896105 3.896105 ZT20-23 3.3521 3.3521 3.3521