condition mean min max ZT0-3 10.155295 10.155295 10.155295 ZT4-7 9.1010965 9.1010965 9.1010965 ZT8-11 10.925483499999999 10.925483499999999 10.925483499999999 ZT12-15 9.6537905 9.6537905 9.6537905 ZT16-19 9.2718865 9.2718865 9.2718865 ZT20-23 10.0946255 10.0946255 10.0946255