condition mean min max ZT0-3 6.882018333333334 3.65046 13.080400000000001 ZT4-7 8.411449999999999 8.411449999999999 8.411449999999999 ZT8-11 5.43135 5.43135 5.43135 ZT12-15 12.173575 11.57995 12.767199999999999 ZT16-19 6.660015 6.660015 6.660015 ZT20-23 8.4757 8.4757 8.4757