condition mean min max ZT0-3 17.432166 17.432166 17.432166 ZT4-7 13.588408000000001 13.588408000000001 13.588408000000001 ZT8-11 13.6439925 13.6439925 13.6439925 ZT12-15 13.050125 13.050125 13.050125 ZT16-19 10.691835000000001 10.691835000000001 10.691835000000001 ZT20-23 11.808537 11.808537 11.808537