condition mean min max ZT0-3 12.075047 12.075047 12.075047 ZT4-7 12.426772 12.426772 12.426772 ZT8-11 11.3017975 11.3017975 11.3017975 ZT12-15 11.7729885 11.7729885 11.7729885 ZT16-19 13.2557815 13.2557815 13.2557815 ZT20-23 12.7364255 12.7364255 12.7364255