condition mean min max ZT0-3 2.124135 2.0028449999999998 2.245425 ZT4-7 2.36159 2.36159 2.36159 ZT8-11 3.307525 3.307525 3.307525 ZT12-15 0 0 0 ZT16-19 2.7889 2.7889 2.7889 ZT20-23 2.5849 2.5849 2.5849