condition mean min max ZT0-3 2.301185 2.291365 2.3110049999999998 ZT4-7 3.95907 3.95907 3.95907 ZT8-11 4.664325 4.664325 4.664325 ZT12-15 0 0 0 ZT16-19 3.6677400000000002 3.6677400000000002 3.6677400000000002 ZT20-23 4.33499 4.33499 4.33499