condition mean min max ZT0-3 8.407335 8.407335 8.407335 ZT4-7 9.762758999999999 9.762758999999999 9.762758999999999 ZT8-11 9.3518325 9.3518325 9.3518325 ZT12-15 9.401921999999999 9.401921999999999 9.401921999999999 ZT16-19 9.900002 9.900002 9.900002 ZT20-23 9.5385625 9.5385625 9.5385625