condition mean min max ZT0-3 2.415725 2.415725 2.415725 ZT4-7 2.622585 2.622585 2.622585 ZT8-11 2.0918200000000002 2.0918200000000002 2.0918200000000002 ZT12-15 1.455875 1.455875 1.455875 ZT16-19 3.497535 3.497535 3.497535 ZT20-23 1.785015 1.785015 1.785015