condition mean min max ZT0-3 11.549702357000001 10.078864574 13.02054014 ZT4-7 5.8538921805 5.774330440666667 5.933453920333333 ZT8-11 4.161924418166667 3.044882003 5.2789668333333335 ZT12-15 4.268265866 3.759373279 4.777158453 ZT16-19 5.3686447795 4.602621363666667 6.134668195333333 ZT20-23 9.395392396 7.904753062 10.886031730000001