condition mean min max ZT0-3 6.628830849 4.03636499 9.221296707999999 ZT4-7 8.20647585875 6.1363014155 10.276650302 ZT8-11 16.9558389225 14.55131229 19.360365555 ZT12-15 18.766252085 17.90326522 19.62923895 ZT16-19 17.329352395 15.618240835000002 19.040463955 ZT20-23 15.014102509999999 13.36127638 16.66692864