condition mean min max ZT0-3 12.944109 12.944109 12.944109 ZT4-7 11.805043 11.805043 11.805043 ZT8-11 12.5770585 12.5770585 12.5770585 ZT12-15 10.838331499999999 10.838331499999999 10.838331499999999 ZT16-19 11.639728 11.639728 11.639728 ZT20-23 11.805043 11.805043 11.805043