condition mean min max ZT0-3 9.238793333333334 7.508125 10.44183 ZT4-7 6.268065 6.268065 6.268065 ZT8-11 5.478205 5.478205 5.478205 ZT12-15 7.67108 6.875865 8.466295 ZT16-19 8.0658 8.0658 8.0658 ZT20-23 9.790845000000001 9.790845000000001 9.790845000000001