Frequencies for first 10,000 rows of prov2210 variable in pos2009 dataset :

       SRV: |
 LABORATORY |
 (CLINICAL) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,638       86.38       86.38
          0 |         55        0.55       86.93
          1 |        915        9.15       96.08
          2 |        256        2.56       98.64
          3 |        136        1.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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