condition mean min max ZT0-3 9.411833 9.411833 9.411833 ZT4-7 10.784241999999999 10.784241999999999 10.784241999999999 ZT8-11 9.50838 9.50838 9.50838 ZT12-15 8.390004999999999 8.390004999999999 8.390004999999999 ZT16-19 9.75892 9.75892 9.75892 ZT20-23 10.986668 10.986668 10.986668