condition mean min max ZT0-3 18.831354 18.831354 18.831354 ZT4-7 14.6366075 14.6366075 14.6366075 ZT8-11 12.89499 12.89499 12.89499 ZT12-15 14.328316000000001 14.328316000000001 14.328316000000001 ZT16-19 15.5146175 15.5146175 15.5146175 ZT20-23 18.472892 18.472892 18.472892