condition mean min max ZT0-3 3.576293628 3.048986691 4.103600565 ZT4-7 3.752425497 3.3504757825 4.1543752115 ZT8-11 2.97988325325 2.6401358795 3.3196306270000004 ZT12-15 1.99467568 1.9082496865 2.0811016735 ZT16-19 3.143098385 2.5977182030000003 3.6884785669999998 ZT20-23 4.4496057715 4.41129596 4.4879155829999995