Frequencies for first 10,000 rows of prov2210 variable in pos1997 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,792       87.92       87.92
          0 |         10        0.10       88.02
          1 |        883        8.83       96.85
          2 |        241        2.41       99.26
          3 |         74        0.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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