condition mean min max ZT0-3 20.165241395 18.46759774 21.86288505 ZT4-7 11.58386638925 11.4009327335 11.766800045 ZT8-11 14.16349369 11.652113975 16.674873405 ZT12-15 10.60624261325 9.811950487 11.400534739500001 ZT16-19 9.107965442 8.443751842 9.772179042 ZT20-23 11.859047205 11.326101340000001 12.39199307