condition mean min max ZT0-3 4.87653398825 4.64748286 5.1055851165 ZT4-7 5.470986012166667 5.437612968 5.5043590563333336 ZT8-11 6.479402124666667 6.166315987 6.792488262333333 ZT12-15 6.7540941045 6.583793946 6.924394263 ZT16-19 6.5557347754999995 6.4108957570000005 6.700573793999999 ZT20-23 5.4017534555 5.046312978333333 5.757193932666667