condition mean min max ZT0-3 12.670033333333333 11.5191 14.8083 ZT4-7 19.1453 19.1453 19.1453 ZT8-11 19.632550000000002 19.632550000000002 19.632550000000002 ZT12-15 19.642325 14.8921 24.39255 ZT16-19 18.2009 18.2009 18.2009 ZT20-23 17.3706 17.3706 17.3706