condition mean min max ZT0-3 17.953596666666666 9.15673 35.463499999999996 ZT4-7 15.47305 15.47305 15.47305 ZT8-11 9.290144999999999 9.290144999999999 9.290144999999999 ZT12-15 15.684875 5.6649 25.70485 ZT16-19 1.762615 1.762615 1.762615 ZT20-23 2.29038 2.29038 2.29038