Frequencies for first 10,000 rows of prov2210 variable in pos2007 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,682       86.82       86.82
          0 |         40        0.40       87.22
          1 |        913        9.13       96.35
          2 |        250        2.50       98.85
          3 |        115        1.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017