condition mean min max ZT0-3 6.159157499999999 6.00889 6.309424999999999 ZT4-7 6.254765 6.254765 6.254765 ZT8-11 6.841290000000001 6.841290000000001 6.841290000000001 ZT12-15 0 0 0 ZT16-19 8.615805 8.615805 8.615805 ZT20-23 9.484010000000001 9.484010000000001 9.484010000000001