condition mean min max ZT0-3 28.849875 27.5631 30.136650000000003 ZT4-7 21.63935 21.63935 21.63935 ZT8-11 25.0721 25.0721 25.0721 ZT12-15 0 0 0 ZT16-19 37.19505 37.19505 37.19505 ZT20-23 28.17005 28.17005 28.17005