condition mean min max ZT0-3 1.1403683333333334 0.810867 1.66751 ZT4-7 1.1855755000000001 1.1855755000000001 1.1855755000000001 ZT8-11 1.9314649999999998 1.9314649999999998 1.9314649999999998 ZT12-15 2.5402725000000004 2.1068800000000003 2.973665 ZT16-19 1.776445 1.776445 1.776445 ZT20-23 1.952795 1.952795 1.952795