Frequencies for first 10,000 rows of prov2210 variable in pos2004 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,766       87.66       87.66
          0 |         10        0.10       87.76
          1 |        866        8.66       96.42
          2 |        249        2.49       98.91
          3 |        109        1.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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