condition mean min max ZT0-3 14.75 14.75 14.75 ZT4-7 19.2 19.2 19.2 ZT8-11 31.6 31.6 31.6 ZT12-15 21.45 21.45 21.45 ZT16-19 18.2 18.2 18.2 ZT20-23 51.6 51.6 51.6