condition mean min max ZT0-3 3.2843833333333334 2.303925 3.84417 ZT4-7 2.28192 2.28192 2.28192 ZT8-11 2.328515 2.328515 2.328515 ZT12-15 3.2361874999999998 3.11428 3.358095 ZT16-19 3.26824 3.26824 3.26824 ZT20-23 5.1491050000000005 5.1491050000000005 5.1491050000000005