condition mean min max ZT0-3 3.176775 3.16996 3.18359 ZT4-7 2.82777 2.82777 2.82777 ZT8-11 13.68965 13.68965 13.68965 ZT12-15 0 0 0 ZT16-19 4.1713249999999995 4.1713249999999995 4.1713249999999995 ZT20-23 2.12133 2.12133 2.12133