condition mean min max ZT0-3 0.49087933333333333 0.2842005 0.797374 ZT4-7 0.5673509999999999 0.5673509999999999 0.5673509999999999 ZT8-11 0.78082 0.78082 0.78082 ZT12-15 1.5405075 1.318935 1.76208 ZT16-19 2.31072 2.31072 2.31072 ZT20-23 2.32139 2.32139 2.32139