condition mean min max ZT0-3 14.859803333333334 7.40756 18.874850000000002 ZT4-7 8.836575 8.836575 8.836575 ZT8-11 7.794644999999999 7.794644999999999 7.794644999999999 ZT12-15 11.3859775 10.268655 12.5033 ZT16-19 12.1594 12.1594 12.1594 ZT20-23 16.8951 16.8951 16.8951