condition mean min max ZT0-3 3.25360687375 3.14652497 3.3606887775 ZT4-7 3.261724203 2.843751617 3.6796967890000003 ZT8-11 2.46204475525 1.9891723495 2.934917161 ZT12-15 2.09611283775 1.4343470699999998 2.7578786055 ZT16-19 5.126630277249999 4.079222162 6.1740383925 ZT20-23 8.316957456499999 8.070108945 8.563805968