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

       SRV: |
 LABORATORY |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      7,849       78.49       78.49
          0 |      1,466       14.66       93.15
          1 |         77        0.77       93.92
          2 |        565        5.65       99.57
          3 |         43        0.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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