condition mean min max ZT0-3 7.6459925 6.569235 8.72275 ZT4-7 17.41125 17.41125 17.41125 ZT8-11 28.281950000000002 28.281950000000002 28.281950000000002 ZT12-15 0 0 0 ZT16-19 23.997799999999998 23.997799999999998 23.997799999999998 ZT20-23 17.67875 17.67875 17.67875