condition mean min max ZT0-3 6.128413321666667 6.10651906 6.150307583333333 ZT4-7 7.787604439999999 7.780794668333333 7.794414211666666 ZT8-11 7.470308747000001 6.332217659 8.608399835 ZT12-15 6.827995572000001 6.8204401 6.835551044000001 ZT16-19 8.9119199285 7.789243674333333 10.034596182666666 ZT20-23 7.649509994166667 6.614949469 8.684070519333334