condition mean min max ZT0-3 18.1637 18.1637 18.1637 ZT4-7 14.0748 14.0748 14.0748 ZT8-11 14.51485 14.51485 14.51485 ZT12-15 14.26355 14.26355 14.26355 ZT16-19 20.193849999999998 20.193849999999998 20.193849999999998 ZT20-23 19.87975 19.87975 19.87975