condition mean min max ZT0-3 13.945585 13.945585 13.945585 ZT4-7 12.715888 12.715888 12.715888 ZT8-11 11.913376 11.913376 11.913376 ZT12-15 11.8522835 11.8522835 11.8522835 ZT16-19 11.4772545 11.4772545 11.4772545 ZT20-23 10.098708 10.098708 10.098708