condition mean min max ZT0-3 3.56 3.56 3.56 ZT4-7 2.477905 2.477905 2.477905 ZT8-11 2.487445 2.487445 2.487445 ZT12-15 3.330085 3.330085 3.330085 ZT16-19 4.3157250000000005 4.3157250000000005 4.3157250000000005 ZT20-23 3.60099 3.60099 3.60099