condition mean min max ZT0-3 10.338536159499998 8.821688468 11.855383851 ZT4-7 8.3604950005 8.310681745666667 8.410308255333334 ZT8-11 8.811266122333333 8.781585233 8.840947011666668 ZT12-15 8.1511818245 7.292285455333333 9.010078193666667 ZT16-19 7.2410047639999995 6.821970047 7.660039481 ZT20-23 6.4153244565000005 6.40343554 6.427213373