condition mean min max ZT0-3 5.4205203829999995 5.24211517 5.598925596 ZT4-7 5.6776420734999995 5.64080188 5.714482267 ZT8-11 6.019780468166667 5.8232542516666665 6.216306684666667 ZT12-15 6.02841304 5.958060135999999 6.098765944 ZT16-19 6.339794881333334 6.317574020333334 6.362015742333334 ZT20-23 6.629708510166667 6.151644260333334 7.1077727600000005