condition mean min max ZT0-3 18.4391 15.44625 21.43195 ZT4-7 17.01945 17.01945 17.01945 ZT8-11 10.60312 10.60312 10.60312 ZT12-15 0 0 0 ZT16-19 6.252705 6.252705 6.252705 ZT20-23 14.8092 14.8092 14.8092