condition mean min max ZT0-3 6.76336 6.369339999999999 7.15738 ZT4-7 6.1358 6.1358 6.1358 ZT8-11 5.040955 5.040955 5.040955 ZT12-15 0 0 0 ZT16-19 6.894615 6.894615 6.894615 ZT20-23 6.49024 6.49024 6.49024