condition mean min max ZT0-3 12.032821 12.032821 12.032821 ZT4-7 14.5560785 14.5560785 14.5560785 ZT8-11 14.738919 14.738919 14.738919 ZT12-15 13.784634 13.784634 13.784634 ZT16-19 14.581536 14.581536 14.581536 ZT20-23 12.660049 12.660049 12.660049