condition mean min max ZT0-3 14.258766666666666 13.63905 14.98335 ZT4-7 8.04972 8.04972 8.04972 ZT8-11 5.10257 5.10257 5.10257 ZT12-15 9.725005 8.65261 10.7974 ZT16-19 8.073129999999999 8.073129999999999 8.073129999999999 ZT20-23 12.96635 12.96635 12.96635