condition mean min max ZT0-3 18.995967967 12.572949893999999 25.41898604 ZT4-7 3.1182688020000002 2.2589123375 3.9776252665000005 ZT8-11 3.06708365075 1.8841568465 4.250010455 ZT12-15 4.08315848 4.0158428535 4.1504741065 ZT16-19 4.90395752575 4.4535044575 5.354410593999999 ZT20-23 7.82057934975 7.7777671635 7.863391536