condition mean min max ZT0-3 66.395806 66.395806 66.395806 ZT4-7 67.818309 67.818309 67.818309 ZT8-11 69.8448475 69.8448475 69.8448475 ZT12-15 60.934785500000004 60.934785500000004 60.934785500000004 ZT16-19 77.633182 77.633182 77.633182 ZT20-23 65.3455975 65.3455975 65.3455975