Frequencies for first 10,000 rows of lab_srvc_cd variable in pos2005 dataset :

       srv: |
 laboratory |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      7,637       76.37       76.37
          0 |      1,380       13.80       90.17
          1 |        146        1.46       91.63
          2 |        793        7.93       99.56
          3 |         44        0.44      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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