condition mean min max ZT0-3 17.45205 15.97915 18.92495 ZT4-7 17.6961 17.6961 17.6961 ZT8-11 17.2103 17.2103 17.2103 ZT12-15 0 0 0 ZT16-19 17.6093 17.6093 17.6093 ZT20-23 21.444200000000002 21.444200000000002 21.444200000000002