condition mean min max ZT0-3 12.936995 12.936995 12.936995 ZT4-7 16.0764655 16.0764655 16.0764655 ZT8-11 15.530353999999999 15.530353999999999 15.530353999999999 ZT12-15 16.6916945 16.6916945 16.6916945 ZT16-19 14.738036000000001 14.738036000000001 14.738036000000001 ZT20-23 16.70372 16.70372 16.70372