condition mean min max ZT0-3 1.295915 1.295915 1.295915 ZT4-7 0.736667 0.736667 0.736667 ZT8-11 1.0448935 1.0448935 1.0448935 ZT12-15 2.69151 2.69151 2.69151 ZT16-19 1.94628 1.94628 1.94628 ZT20-23 2.9181049999999997 2.9181049999999997 2.9181049999999997