Frequencies for first 10,000 rows of prov2210 variable in pos1995 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,933       89.33       89.33
          0 |          9        0.09       89.42
          1 |        791        7.91       97.33
          2 |        207        2.07       99.40
          3 |         60        0.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016