Frequencies for first 10,000 rows of prov2210 variable in pos1993 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,856       88.56       88.56
          0 |         10        0.10       88.66
          1 |        865        8.65       97.31
          2 |        208        2.08       99.39
          3 |         61        0.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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