condition mean min max ZT0-3 5.866515 4.09156 7.64147 ZT4-7 2.2008199999999998 2.2008199999999998 2.2008199999999998 ZT8-11 5.415455 5.415455 5.415455 ZT12-15 0 0 0 ZT16-19 3.744045 3.744045 3.744045 ZT20-23 3.76028 3.76028 3.76028