condition mean min max ZT0-3 8.44124632025 7.474867592 9.4076250485 ZT4-7 7.686454484 7.193550673666667 8.179358294333333 ZT8-11 8.186267954 7.949750975 8.422784933 ZT12-15 8.240803125333333 7.986324847 8.495281403666667 ZT16-19 10.004098991333333 9.954086029666666 10.054111953 ZT20-23 10.406623905 9.86228103 10.95096678