condition mean min max ZT0-3 2.2882925 1.6750599999999998 2.9015250000000004 ZT4-7 2.065755 2.065755 2.065755 ZT8-11 3.26382 3.26382 3.26382 ZT12-15 0 0 0 ZT16-19 3.10282 3.10282 3.10282 ZT20-23 3.3715 3.3715 3.3715