condition mean min max ZT0-3 1.2415908333333332 0.8074379999999999 1.621025 ZT4-7 1.5768650000000002 1.5768650000000002 1.5768650000000002 ZT8-11 6.71718 6.71718 6.71718 ZT12-15 5.48028 2.269225 8.691334999999999 ZT16-19 2.300455 2.300455 2.300455 ZT20-23 1.510035 1.510035 1.510035