condition mean min max ZT0-3 19.057299999999998 17.09755 21.01705 ZT4-7 12.3946 12.3946 12.3946 ZT8-11 14.912700000000001 14.912700000000001 14.912700000000001 ZT12-15 0 0 0 ZT16-19 19.88485 19.88485 19.88485 ZT20-23 17.00375 17.00375 17.00375