condition mean min max ZT0-3 6.83099999075 3.5856485615 10.07635142 ZT4-7 4.1422243665 3.14165178 5.1427969529999995 ZT8-11 6.725412007999999 4.8382312715 8.612592744499999 ZT12-15 10.088419422 7.4542473535 12.7225914905 ZT16-19 13.914877585 13.033904605 14.795850564999999 ZT20-23 24.875920677499998 21.401177054999998 28.350664300000002