condition mean min max ZT0-3 9.126505 7.99531 10.2577 ZT4-7 7.94713 7.94713 7.94713 ZT8-11 12.949649999999998 12.949649999999998 12.949649999999998 ZT12-15 0 0 0 ZT16-19 16.6277 16.6277 16.6277 ZT20-23 13.5533 13.5533 13.5533