condition mean min max ZT0-3 21.1 21.1 21.1 ZT4-7 48.4 48.4 48.4 ZT8-11 36.3 36.3 36.3 ZT12-15 40.0 40.0 40.0 ZT16-19 28.5 28.5 28.5 ZT20-23 14.0 14.0 14.0