condition mean min max ZT0-3 12.641125 12.54475 12.7375 ZT4-7 10.04175 10.04175 10.04175 ZT8-11 8.448225 8.448225 8.448225 ZT12-15 0 0 0 ZT16-19 18.98005 18.98005 18.98005 ZT20-23 19.25965 19.25965 19.25965