condition mean min max ZT0-3 7.317796631249999 6.470615672999999 8.1649775895 ZT4-7 4.72653636175 4.3819780134999995 5.07109471 ZT8-11 8.51916167825 5.825205861500001 11.213117494999999 ZT12-15 13.45864657625 11.9697708925 14.94752226 ZT16-19 15.359989362499999 13.797890375 16.92208835 ZT20-23 23.41234056 22.35547562 24.4692055