condition mean min max ZT0-3 0.818531 0.810494 0.826568 ZT4-7 0.2769045 0.2769045 0.2769045 ZT8-11 0.440552 0.440552 0.440552 ZT12-15 0 0 0 ZT16-19 1.626065 1.626065 1.626065 ZT20-23 1.41553 1.41553 1.41553