condition mean min max ZT0-3 15.05465 13.07965 17.958350000000003 ZT4-7 14.9786 14.9786 14.9786 ZT8-11 7.729305 7.729305 7.729305 ZT12-15 9.0243125 5.959075 12.08955 ZT16-19 4.766525 4.766525 4.766525 ZT20-23 7.278169999999999 7.278169999999999 7.278169999999999