condition mean min max ZT0-3 1.7584499999999998 1.635305 1.881595 ZT4-7 2.1760149999999996 2.1760149999999996 2.1760149999999996 ZT8-11 1.7278250000000002 1.7278250000000002 1.7278250000000002 ZT12-15 0 0 0 ZT16-19 2.30835 2.30835 2.30835 ZT20-23 2.387135 2.387135 2.387135