condition mean min max ZT0-3 32.6 32.6 32.6 ZT4-7 14.5 14.5 14.5 ZT8-11 13.65 13.65 13.65 ZT12-15 15.65 15.65 15.65 ZT16-19 19.549999999999997 19.549999999999997 19.549999999999997 ZT20-23 39.0 39.0 39.0