condition mean min max ZT0-3 58.9640862 51.33588114 66.59229126 ZT4-7 34.5442460675 33.6416835 35.446808635 ZT8-11 24.393539269999998 20.29969074 28.4873878 ZT12-15 12.47767095275 10.2302185695 14.725123336000001 ZT16-19 46.694135585 33.427835245 59.960435925 ZT20-23 91.0317320925 88.87882585 93.18463833499999