condition mean min max ZT0-3 19.555579 19.555579 19.555579 ZT4-7 19.601468500000003 19.601468500000003 19.601468500000003 ZT8-11 21.741193000000003 21.741193000000003 21.741193000000003 ZT12-15 17.328191 17.328191 17.328191 ZT16-19 19.5620145 19.5620145 19.5620145 ZT20-23 18.861978999999998 18.861978999999998 18.861978999999998