condition mean min max ZT0-3 4.425013333333333 3.62599 4.83972 ZT4-7 3.081455 3.081455 3.081455 ZT8-11 2.6361 2.6361 2.6361 ZT12-15 4.53993 4.235415 4.844445 ZT16-19 3.863605 3.863605 3.863605 ZT20-23 4.7197499999999994 4.7197499999999994 4.7197499999999994