condition mean min max ZT0-3 7.948445 7.565215 8.331675 ZT4-7 25.77375 25.77375 25.77375 ZT8-11 69.5709 69.5709 69.5709 ZT12-15 0 0 0 ZT16-19 14.1024 14.1024 14.1024 ZT20-23 14.7739 14.7739 14.7739