condition mean min max ZT0-3 17.867289 17.867289 17.867289 ZT4-7 16.38504 16.38504 16.38504 ZT8-11 18.736780500000002 18.736780500000002 18.736780500000002 ZT12-15 21.6359105 21.6359105 21.6359105 ZT16-19 17.357973 17.357973 17.357973 ZT20-23 16.642516999999998 16.642516999999998 16.642516999999998