condition mean min max ZT0-3 2.4081099999999998 2.4081099999999998 2.4081099999999998 ZT4-7 3.334415 3.334415 3.334415 ZT8-11 4.5956399999999995 4.5956399999999995 4.5956399999999995 ZT12-15 2.2762000000000002 2.2762000000000002 2.2762000000000002 ZT16-19 1.178105 1.178105 1.178105 ZT20-23 1.6302949999999998 1.6302949999999998 1.6302949999999998