condition mean min max ZT0-3 17.92035 17.30875 18.531950000000002 ZT4-7 11.8159 11.8159 11.8159 ZT8-11 13.5638 13.5638 13.5638 ZT12-15 0 0 0 ZT16-19 17.87425 17.87425 17.87425 ZT20-23 20.5513 20.5513 20.5513