condition mean min max ZT0-3 8.559562015249998 8.34845169 8.770672340499999 ZT4-7 6.095698435749999 5.899878129499999 6.291518741999999 ZT8-11 10.489912643 7.871871897 13.107953389 ZT12-15 21.280670507499998 19.41456633 23.146774685 ZT16-19 22.2992852825 20.688219545 23.91035102 ZT20-23 31.420728885 25.676423045 37.165034725