condition mean min max ZT0-3 3.0576383333333332 2.429 3.618685 ZT4-7 3.131525 3.131525 3.131525 ZT8-11 2.0217549999999997 2.0217549999999997 2.0217549999999997 ZT12-15 2.3824674999999997 1.88998 2.874955 ZT16-19 2.28297 2.28297 2.28297 ZT20-23 3.0320099999999996 3.0320099999999996 3.0320099999999996