Frequencies for first 10,000 rows of prov2210 variable in pos2001 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,837       88.37       88.37
          0 |          9        0.09       88.46
          1 |        835        8.35       96.81
          2 |        237        2.37       99.18
          3 |         82        0.82      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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