condition mean min max ZT0-3 16.354585 16.354585 16.354585 ZT4-7 4.2231000000000005 4.2231000000000005 4.2231000000000005 ZT8-11 3.1553999999999998 3.1553999999999998 3.1553999999999998 ZT12-15 22.23575 22.23575 22.23575 ZT16-19 6.258115 6.258115 6.258115 ZT20-23 31.7697 31.7697 31.7697