condition mean min max ZT0-3 6.723744999999999 5.8231649999999995 7.624325 ZT4-7 5.03915 5.03915 5.03915 ZT8-11 4.041605000000001 4.041605000000001 4.041605000000001 ZT12-15 0 0 0 ZT16-19 7.75033 7.75033 7.75033 ZT20-23 8.635425 8.635425 8.635425