condition mean min max ZT0-3 1.466305 1.383445 1.549165 ZT4-7 0.919311 0.919311 0.919311 ZT8-11 0.560913 0.560913 0.560913 ZT12-15 0 0 0 ZT16-19 4.158825 4.158825 4.158825 ZT20-23 1.490935 1.490935 1.490935