condition mean min max ZT0-3 9.698721 9.698721 9.698721 ZT4-7 9.602469500000002 9.602469500000002 9.602469500000002 ZT8-11 9.459599 9.459599 9.459599 ZT12-15 9.0398985 9.0398985 9.0398985 ZT16-19 9.475999999999999 9.475999999999999 9.475999999999999 ZT20-23 9.896392 9.896392 9.896392