condition mean min max ZT0-3 7.84374981825 7.759885846 7.9276137905 ZT4-7 6.635011027000001 4.8918690190000005 8.378153035 ZT8-11 9.400792693249999 9.021646002499999 9.779939383999999 ZT12-15 7.142615652749999 6.815299947 7.469931358499999 ZT16-19 10.169439585500001 8.1857913015 12.1530878695 ZT20-23 15.0551675625 14.707019930000001 15.403315195