condition mean min max ZT0-3 3.382370203 2.086898309 4.677842097 ZT4-7 10.956761572 7.5650354339999994 14.34848771 ZT8-11 25.94387286 23.13465405 28.75309167 ZT12-15 13.093531700499998 8.3982741145 17.7887892865 ZT16-19 4.0177646585 3.3308939019999997 4.704635415 ZT20-23 2.6611111425 2.078673587 3.2435486979999997