condition mean min max ZT0-3 2.9289783333333332 2.60208 3.407585 ZT4-7 3.0646750000000003 3.0646750000000003 3.0646750000000003 ZT8-11 2.9787150000000002 2.9787150000000002 2.9787150000000002 ZT12-15 3.9883475 3.593865 4.38283 ZT16-19 3.35079 3.35079 3.35079 ZT20-23 3.545215 3.545215 3.545215