condition mean min max ZT0-3 17.058355595000002 16.38276656 17.73394463 ZT4-7 13.718229661 12.761412002 14.675047320000001 ZT8-11 21.2916656625 17.128556175 25.45477515 ZT12-15 18.8469394425 16.15887024 21.535008644999998 ZT16-19 13.4017710875 12.287860755 14.51568142 ZT20-23 17.554415300000002 15.787892245000002 19.320938355000003