condition mean min max ZT0-3 2.51427 2.51427 2.51427 ZT4-7 5.46821 5.46821 5.46821 ZT8-11 2.24231 2.24231 2.24231 ZT12-15 1.256901 1.256901 1.256901 ZT16-19 0.3374865 0.3374865 0.3374865 ZT20-23 0.9798285 0.9798285 0.9798285