condition mean min max ZT0-3 15.663284 15.663284 15.663284 ZT4-7 26.956527 26.956527 26.956527 ZT8-11 30.774474 30.774474 30.774474 ZT12-15 21.862244 21.862244 21.862244 ZT16-19 18.9346635 18.9346635 18.9346635 ZT20-23 19.4892515 19.4892515 19.4892515