condition mean min max ZT0-3 7.5562325 6.678075 8.43439 ZT4-7 7.638925 7.638925 7.638925 ZT8-11 11.18855 11.18855 11.18855 ZT12-15 0 0 0 ZT16-19 17.7421 17.7421 17.7421 ZT20-23 11.25815 11.25815 11.25815