condition mean min max ZT0-3 14.51635 14.51635 14.51635 ZT4-7 12.04545 12.04545 12.04545 ZT8-11 14.20605 14.20605 14.20605 ZT12-15 18.26545 18.26545 18.26545 ZT16-19 27.93755 27.93755 27.93755 ZT20-23 16.06075 16.06075 16.06075