condition mean min max ZT0-3 1.9296185 1.0539455 2.4941649999999997 ZT4-7 1.2305000000000001 1.2305000000000001 1.2305000000000001 ZT8-11 1.840795 1.840795 1.840795 ZT12-15 3.3653525 3.262825 3.46788 ZT16-19 3.3488800000000003 3.3488800000000003 3.3488800000000003 ZT20-23 2.9518050000000002 2.9518050000000002 2.9518050000000002