condition mean min max ZT0-3 4.86344 3.3575 6.152915 ZT4-7 6.68201 6.68201 6.68201 ZT8-11 13.4394 13.4394 13.4394 ZT12-15 11.744375 10.67595 12.8128 ZT16-19 10.629945 10.629945 10.629945 ZT20-23 8.932604999999999 8.932604999999999 8.932604999999999