condition mean min max ZT0-3 28.348675 24.9514 31.74595 ZT4-7 19.08785 19.08785 19.08785 ZT8-11 14.6146 14.6146 14.6146 ZT12-15 0 0 0 ZT16-19 22.6858 22.6858 22.6858 ZT20-23 21.8175 21.8175 21.8175