condition mean min max ZT0-3 3.2655516666666666 1.713395 6.2126149999999996 ZT4-7 2.55781 2.55781 2.55781 ZT8-11 2.305065 2.305065 2.305065 ZT12-15 2.4354 1.81624 3.05456 ZT16-19 1.581015 1.581015 1.581015 ZT20-23 1.74965 1.74965 1.74965