condition mean min max ZT0-3 12.5 12.5 12.5 ZT4-7 14.8 14.8 14.8 ZT8-11 57.0 57.0 57.0 ZT12-15 19.6 19.6 19.6 ZT16-19 17.5 17.5 17.5 ZT20-23 43.0 43.0 43.0