condition mean min max ZT0-3 6.0273158347499995 5.705220779999999 6.3494108895 ZT4-7 6.038182274 5.302040928 6.7743236200000005 ZT8-11 7.560365192333333 7.285749208666667 7.834981175999999 ZT12-15 7.8031012935 7.578689705333334 8.027512881666667 ZT16-19 8.974808451000001 8.971168434 8.978448468 ZT20-23 8.115390502833334 7.439913334666667 8.790867671