condition mean min max ZT0-3 6.691649893 3.7467851189999997 9.636514667 ZT4-7 20.157597307499998 15.752730305 24.56246431 ZT8-11 27.077634025000002 25.54867241 28.606595640000002 ZT12-15 26.4099945775 24.812818489999998 28.007170665 ZT16-19 19.264908284999997 17.79483577 20.7349808 ZT20-23 22.8392041975 22.382725569999998 23.295682825