condition mean min max ZT0-3 154.837963 154.837963 154.837963 ZT4-7 217.581874 217.581874 217.581874 ZT8-11 205.06061499999998 205.06061499999998 205.06061499999998 ZT12-15 215.0599585 215.0599585 215.0599585 ZT16-19 200.88129800000002 200.88129800000002 200.88129800000002 ZT20-23 258.823988 258.823988 258.823988