condition mean min max ZT0-3 18.583575 18.3978 18.76935 ZT4-7 17.90265 17.90265 17.90265 ZT8-11 14.0855 14.0855 14.0855 ZT12-15 0 0 0 ZT16-19 17.436 17.436 17.436 ZT20-23 21.571849999999998 21.571849999999998 21.571849999999998