condition mean min max ZT0-3 2.7643133333333334 1.880645 3.306545 ZT4-7 1.7493949999999998 1.7493949999999998 1.7493949999999998 ZT8-11 1.246795 1.246795 1.246795 ZT12-15 1.2277550000000002 1.1305 1.32501 ZT16-19 1.175201 1.175201 1.175201 ZT20-23 2.59369 2.59369 2.59369