condition mean min max ZT0-3 18.9048 14.0813 22.1605 ZT4-7 8.837615 8.837615 8.837615 ZT8-11 13.21545 13.21545 13.21545 ZT12-15 14.06125 13.0673 15.0552 ZT16-19 15.5551 15.5551 15.5551 ZT20-23 21.9488 21.9488 21.9488