condition mean min max ZT0-3 223.735924 223.735924 223.735924 ZT4-7 205.179775 205.179775 205.179775 ZT8-11 223.59355 223.59355 223.59355 ZT12-15 195.266669 195.266669 195.266669 ZT16-19 210.45283899999998 210.45283899999998 210.45283899999998 ZT20-23 241.473549 241.473549 241.473549