sex age    serum   num    tot
M   30-49    A     13     340
M   30-49    B     18     408
M   30-49    C     40     421
M   30-49    D     57     362
M   50-62    A     13     123
M   50-62    B     33     176
M   50-62    C     35     174
M   50-62    D     49     183
F   30-49    A     6      542
F   30-49    B     5      552
F   30-49    C     10     412
F   30-49    D     18     357
F   50-62    A     9       58
F   50-62    B     12     135
F   50-62    C     21     218
F   50-62    D     48     395