condition mean min max ZT0-3 8.289895 8.289895 8.289895 ZT4-7 9.3046 9.3046 9.3046 ZT8-11 3.1137449999999998 3.1137449999999998 3.1137449999999998 ZT12-15 0.9525775 0.9525775 0.9525775 ZT16-19 3.684495 3.684495 3.684495 ZT20-23 6.38072 6.38072 6.38072