condition mean min max ZT0-3 40.8 40.8 40.8 ZT4-7 20.9 20.9 20.9 ZT8-11 19.349999999999998 19.349999999999998 19.349999999999998 ZT12-15 27.85 27.85 27.85 ZT16-19 44.45 44.45 44.45 ZT20-23 21.1 21.1 21.1