condition mean min max ZT0-3 7.5190825 5.792945 9.24522 ZT4-7 8.513035 8.513035 8.513035 ZT8-11 7.597875 7.597875 7.597875 ZT12-15 0 0 0 ZT16-19 2.84696 2.84696 2.84696 ZT20-23 2.010185 2.010185 2.010185