condition mean min max ZT0-3 25.173205 25.173205 25.173205 ZT4-7 21.4131635 21.4131635 21.4131635 ZT8-11 18.6681925 18.6681925 18.6681925 ZT12-15 28.256806 28.256806 28.256806 ZT16-19 16.567805 16.567805 16.567805 ZT20-23 17.3456655 17.3456655 17.3456655