condition mean min max ZT0-3 121.871625 73.95725 169.786 ZT4-7 7.09573 7.09573 7.09573 ZT8-11 2.13166 2.13166 2.13166 ZT12-15 0 0 0 ZT16-19 34.481899999999996 34.481899999999996 34.481899999999996 ZT20-23 38.75105 38.75105 38.75105