condition mean min max ZT0-3 10.947993 10.947993 10.947993 ZT4-7 10.7848255 10.7848255 10.7848255 ZT8-11 11.9297135 11.9297135 11.9297135 ZT12-15 11.800246999999999 11.800246999999999 11.800246999999999 ZT16-19 12.6655915 12.6655915 12.6655915 ZT20-23 12.3779035 12.3779035 12.3779035