condition mean min max ZT0-3 3.30037 3.30037 3.30037 ZT4-7 1.93594 1.93594 1.93594 ZT8-11 3.9743500000000003 3.9743500000000003 3.9743500000000003 ZT12-15 4.849015 4.849015 4.849015 ZT16-19 4.8035250000000005 4.8035250000000005 4.8035250000000005 ZT20-23 3.903385 3.903385 3.903385