condition mean min max ZT0-3 21.5 21.5 21.5 ZT4-7 14.8 14.8 14.8 ZT8-11 16.65 16.65 16.65 ZT12-15 5.75 5.75 5.75 ZT16-19 9.0 9.0 9.0 ZT20-23 17.45 17.45 17.45