condition mean min max ZT0-3 4.0127325 3.28934 4.736125 ZT4-7 5.65039 5.65039 5.65039 ZT8-11 6.0457 6.0457 6.0457 ZT12-15 0 0 0 ZT16-19 7.021215 7.021215 7.021215 ZT20-23 6.238004999999999 6.238004999999999 6.238004999999999