condition mean min max ZT0-3 4.23804 4.22331 4.25277 ZT4-7 4.440825 4.440825 4.440825 ZT8-11 4.62931 4.62931 4.62931 ZT12-15 0 0 0 ZT16-19 4.9812650000000005 4.9812650000000005 4.9812650000000005 ZT20-23 5.18919 5.18919 5.18919