condition mean min max ZT0-3 9.594792499999999 6.544045 12.645539999999999 ZT4-7 12.716663333333333 12.716663333333333 12.716663333333333 ZT8-11 6.7098700000000004 6.7098700000000004 6.7098700000000004 ZT12-15 5.7807125 5.1155100000000004 6.445915 ZT16-19 7.259550000000001 6.2254700000000005 8.29363 ZT20-23 0 0 0