condition mean min max ZT0-3 1.56656475 1.56656475 1.56656475 ZT4-7 1.47943425 1.47943425 1.47943425 ZT8-11 1.780781 1.780781 1.780781 ZT12-15 2.3218305833333335 2.3218305833333335 2.3218305833333335 ZT16-19 2.7041475 2.7041475 2.7041475 ZT20-23 2.06731925 2.06731925 2.06731925