condition mean min max ZT0-3 6.77863 6.225335 7.331925 ZT4-7 5.086875 5.086875 5.086875 ZT8-11 5.283505 5.283505 5.283505 ZT12-15 0 0 0 ZT16-19 7.93696 7.93696 7.93696 ZT20-23 9.012665 9.012665 9.012665