condition mean min max ZT0-3 1.071155 0.530645 1.611665 ZT4-7 0.9295304999999999 0.9295304999999999 0.9295304999999999 ZT8-11 1.09937 1.09937 1.09937 ZT12-15 0 0 0 ZT16-19 1.219015 1.219015 1.219015 ZT20-23 1.2932000000000001 1.2932000000000001 1.2932000000000001