condition mean min max ZT0-3 17.5 17.5 17.5 ZT4-7 10.2 10.2 10.2 ZT8-11 2.9 2.9 2.9 ZT12-15 12.649999999999999 12.649999999999999 12.649999999999999 ZT16-19 36.599999999999994 36.599999999999994 36.599999999999994 ZT20-23 20.7 20.7 20.7