condition mean min max ZT0-3 10.088096 10.088096 10.088096 ZT4-7 9.8391885 9.8391885 9.8391885 ZT8-11 11.128933499999999 11.128933499999999 11.128933499999999 ZT12-15 11.244815 11.244815 11.244815 ZT16-19 10.8188825 10.8188825 10.8188825 ZT20-23 9.5727505 9.5727505 9.5727505