condition mean min max ZT0-3 1.17290275 0.9913354999999999 1.35447 ZT4-7 8.025055 8.025055 8.025055 ZT8-11 15.7701 15.7701 15.7701 ZT12-15 0 0 0 ZT16-19 5.069865 5.069865 5.069865 ZT20-23 3.601215 3.601215 3.601215