condition mean min max ZT0-3 7.683065 7.27754 8.08859 ZT4-7 9.556270000000001 9.556270000000001 9.556270000000001 ZT8-11 8.69865 8.69865 8.69865 ZT12-15 0 0 0 ZT16-19 12.22915 12.22915 12.22915 ZT20-23 9.996525 9.996525 9.996525