condition mean min max ZT0-3 12.791943 12.791943 12.791943 ZT4-7 13.742858 13.742858 13.742858 ZT8-11 15.786041999999998 15.786041999999998 15.786041999999998 ZT12-15 14.157928 14.157928 14.157928 ZT16-19 15.328052 15.328052 15.328052 ZT20-23 14.333667 14.333667 14.333667