condition mean min max ZT0-3 18.795849 18.795849 18.795849 ZT4-7 20.9546685 20.9546685 20.9546685 ZT8-11 18.795849 18.795849 18.795849 ZT12-15 16.342244 16.342244 16.342244 ZT16-19 18.6938635 18.6938635 18.6938635 ZT20-23 20.992932000000003 20.992932000000003 20.992932000000003