condition mean min max ZT0-3 48.65 48.65 48.65 ZT4-7 7.2 7.2 7.2 ZT8-11 21.1 21.1 21.1 ZT12-15 33.5 33.5 33.5 ZT16-19 30.3 30.3 30.3 ZT20-23 20.25 20.25 20.25