condition mean min max ZT0-3 12.275591 12.275591 12.275591 ZT4-7 19.4655585 19.4655585 19.4655585 ZT8-11 9.852178 9.852178 9.852178 ZT12-15 10.8660855 10.8660855 10.8660855 ZT16-19 10.010692 10.010692 10.010692 ZT20-23 9.8375925 9.8375925 9.8375925