condition mean min max ZT0-3 5.606925 5.29917 5.914680000000001 ZT4-7 8.56738 8.56738 8.56738 ZT8-11 10.8188 10.8188 10.8188 ZT12-15 0 0 0 ZT16-19 11.99905 11.99905 11.99905 ZT20-23 9.524675 9.524675 9.524675