condition mean min max ZT0-3 929.628985 929.628985 929.628985 ZT4-7 706.2174705 706.2174705 706.2174705 ZT8-11 838.4450529999999 838.4450529999999 838.4450529999999 ZT12-15 853.5104725 853.5104725 853.5104725 ZT16-19 1290.903853 1290.903853 1290.903853 ZT20-23 1241.4743819999999 1241.4743819999999 1241.4743819999999