condition mean min max ZT0-3 12.43557 12.43557 12.43557 ZT4-7 12.850658 12.850658 12.850658 ZT8-11 12.5886605 12.5886605 12.5886605 ZT12-15 12.652894499999999 12.652894499999999 12.652894499999999 ZT16-19 13.441016 13.441016 13.441016 ZT20-23 12.458827 12.458827 12.458827