condition mean min max ZT0-3 27.999787 27.999787 27.999787 ZT4-7 25.1242485 25.1242485 25.1242485 ZT8-11 22.365581 22.365581 22.365581 ZT12-15 17.9753295 17.9753295 17.9753295 ZT16-19 19.3999425 19.3999425 19.3999425 ZT20-23 16.622826500000002 16.622826500000002 16.622826500000002