condition mean min max ZT0-3 4.449893333333334 4.449893333333334 4.449893333333334 ZT4-7 4.2126850000000005 4.2126850000000005 4.2126850000000005 ZT8-11 4.04576 4.04576 4.04576 ZT12-15 3.6177400000000004 3.6177400000000004 3.6177400000000004 ZT16-19 4.18352 4.18352 4.18352 ZT20-23 4.44831 4.44831 4.44831